Below are links to information about growing your own fish

RAS (Recirculation Aquaculture System)

RAS with flow through

Links that explain water paramenters

Fish food

Fish have a muddy or earthy taste

YouTube video about how to use large pellets to feed small fish

YouTube video of a backyard aquaponic set-up

Thinking of farming fish

Premium client videos   

Members area content   

My YouTube channel

This is a link to the famous Rob Bob Back yard aquaponic information

Fingerling prices are here

My contact details are all here

Click the links below for information about fish for farm dams

My contact details are all here

Click the links below to find detailed information about each species

My contact details are all here

JADE PERCH INFORMATION

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The aquaculture of Jade Perch has become one of the fastest growing freshwater fish species in the world.

Jade perch definately are NOT vegiterian, they are in fact omnivores. They will eat almost anything, animal or vegetable!

Click for recipes and Hints

Jade Perch really seem to grow very fast

 Click for video

Quality fingerlings don't just happen.

Click for video

It all starts with the eggs hatching. In this YouTube video you can see the larvae breaking out of the egg shells. Click here

SEE jadeperchman on YouTube

This fish sure has a great place in commercial aquaculture !

Purging or "finishing"

Like most freshwater fish species jade perch can develop off flavour.

Fish are significant bio accumulators, meaning they gradually build up the chemicals that cause the off flavour from their environment.
Freshwater fish  "drink" through their gills and skin.
This is mainly how the chemicals that cause off flavour enters the fish’ body.

How big do they get?

For detailed information about growing jade perch, and their health management (Disease management.) go to the members area

AQUACULTURE CONSULTINGAdvice is available at your aquaculture site or farm, to existing and potential growers of Australian freshwater fish. Advice is based on over 30 years experience and hands on practice. 

See Perch Man on 

Below, the Gut of a wild JADE perch with all organs visible and NO fat

Below, is an aquacultured jade perch which has been fed on a diet perhaps a little too rich, no organs are visible through the fat

*Keeping the osmotic pressure, the salt in their cells, in freshwater fish is a constant battle and will result is serious stress to the fish if not managed by the grower, or hatchery operator. Fresh water fish constantly face two kinds of problems, they gain water passively through their skin due to osmotic gradient, and continually lose body salts to the surrounding water of much lower salt content. Osmoregulation in fresh water fish is affected by pumping out excess of water from their bodies. The salt loss through the excretion of water is made good by salt absorbing gills, skin and various parts of the alimentary canal.

The members area of this website has detailed information about jade perch, including growing and disease management  

click for more

My contact information is here

Why and when I guarantee live arrival

I do not guarantee live arrival for export shipments, however my packing protocols have been proven over more than 40 years of shipping commercial quantities of live fish.
Also, I conduct packing trials multiple times in every season to confirm my protocols. 

 Click to see unpacking commercial shipments playlist.

Do I guarantee live arrival?

Generally no, however . . . 

• Your written quote must state,"Live arrival IS guaranteed"
• You must provide proof of losses on the day of arrival, not the next day, STRICTLY ON THE DAY OF ARRIVAL
• The proof must be in the form of clear, in focus, HD video at least 2 minutes long.
• The video must clearly show the gills of the fish so I can see that the fish are not breathing.
• The fish must be in the bag they were packed in sealed by us, (As they were packed.) not in your tank or any other container.
• Losses must be significant, not just a few fish.
• If we agree to replace the fish, all shipping costs must be paid by the customer before we send replacements.
• We don't sell boxes or freight, so I can only replace the fish.
• We will not replace fish if there was an issue that was not within our control.

  

Otters are carnivorous mammals, usually entering a fish farm at night, these predators are effective killers and can decimate a pond in a relatively short time.
The only solution is to prohibit entry through electric fencing, or lethal removal, which is probably not permitted in most countries.
An adult otter can eat over 13 pounds of fish every day. (About 5.5 kilos.)
They are known to range large distances (Several kilometers.) in search of food, territory and a mate.
Once they find a food source they will return on a regular basis.
They will kill a large number of fish and eat their fill, then hide what they haven't eaten, and return later to feed on them.

To eliminate access to ponds you could build a fence, which may be expensive or impractical depending on the size of the farm.  
A sturdy, 4-foot-high fence constructed with 3-inch wire mesh might be sufficient.
Bury the bottom edge at least 150 centimeters in the ground or use a wire apron on the outside of the fence to keep otters from digging under the fence.

Fish farmers face challenges in keeping otters away from their stocks.

The ability of otters to climb fences has practical implications. 

Understanding that otters can climb fences suggests that simply erecting a barrier might not be sufficient. 

To effectively deter otters, fences may need to be higher and constructed with materials that are difficult for otters to grip or scale. 

In summary, otters can climb fences. They are naturally agile, very intelligent and are excellent at problem solving. 

Their natural diet is fish, and they are excellent swimmers, jumpers, climbers and diggers. They are the monkeys of the fish pond.

 

OR

 

An electric fence is a highly effective, nonlethal, solution for keeping otters out of ponds. 

Electrified fences, though controversial, are sometimes employed as a deterrent, emphasising the need for effective and humane wildlife management strategies.

 

Use multiple strands, close spacing, and a strong energizer to deter them from jumping, digging under, or going through the fence. 

Run several taut wires.

A five-strand fence should be effective against a very persistent or hungry otter, especially cubs. 

The wire strands should be 10 to 15 centimeters apart and the bottom strand should be close enough to the ground that they can't move under the fence.

The energizer needs sufficient power, at least 1 Joule for effective shock, especially against predators like otters.

Energisers are available that are solar powered, mains powered and battery powered. (Car batteries are best.)

 
Wires: Use at least five strands, spaced about  10 to 15 centimeters apart, with the bottom wire low to the ground. 

Ensure the wires are kept weed-free for proper grounding. There are several types of wire available and they come in rolls that can be kilometers long, and very cheap.

Below, multi-strand stainless steel wire     

Polly rope with stainless steel conductors

  

Braided wire on the roll and a close up view.

Insulators for mounting wires on posts, with stand-off insulators on the outer side preventing climbing, or run the wires through insulators or a short length of PVC or polly pipe, it's cheap to buy and easy to cut into short lengths. Otters will climb so the insulators should be as short as practicable. 

Many types of insulators are available on the market, including screw-in for wood posts, and polly for any type of post.

  

Below: extended insulator                               

 

Below: Corner pully insulator

Weed Control: Keep vegetation clear from the wires to prevent grounding and loss of charge.
Outflow pipes from the farm that are big enough for otters to move through should be closed off with solid wire that otters can't break through.

 

The right posts  will make a difference. Wires must be kept tight and correctly insulated to function effectively. 
Plastic Electric Fence Posts, no need for insulators

• Lightweight, easy to move, and UV-stabilised.
• Ideal for emergency temporary fencing, quickly installed around a pond.

 

Metal Electric Fence Posts

• Strong, durable, and suitable for permanent electric fencing.
• Great for boundary fences and this would also keep larger animals, particularly cattle, out of ponds.
• Rust-resistant and long-lasting.
• PVC fence posts easy and cheap to make yourself.

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To see full size pictures, right click and open in new tab. My contact details are all here

Below are the current prices for commercial quantities.

For export shipments there is a minimum Australian dollar value of $3,000.

THE FOLLOWING PRICES APPLY TO BULK ORDERS OF JADE PERCH AND SILVER PERCH

F1 fry are available for jade perch.

See this webpage for information about F1 fry Minimum order 10,000 tails. au$1.15 each.

I can ship to almost any country subject to local authority regulations.

 When and why I do or do NOT guarantee live arrival.

My contact details are all here

Ammonia

Ammonia is part of the nitrogen cycle. The cycle is, ammonia to nitrite to nitrate. 

Ammonia exists in two forms in the water, ammonia or ammonium. Ammonia is very dangerous to fish. Ammonium is pretty much harmless to fish. Ammonia exists as ammonium in low pH. I try to keep fish in a pH of 6.50 to 7.00. Never more than 7.20. 

Ammonia usually occurs when organic matter decomposes. Toxicity increases as pH increases and as temperature increases. Plants are more tolerant of ammonia than animals, and invertebrates are more tolerant than fish. Hatching and growth rates of fishes may be affected. 

Excess ammonia levels is thought to be one of the main causes of unexplained losses in fish hatcheries. Fish may suffer a loss of equilibrium, hyperexcitability, (Hyperexcitability is a state where neurons are more easily activated by stimuli, leading to excessive firing and a heightened response to stimuli. This condition can manifest as muscle stiffness or spasms.) increased respiratory activity and oxygen uptake, and increased heart rate. At extreme ammonia levels, fish may experience convulsions, coma, and death. 
At higher levels even relatively short exposures can lead to skin, eye, and gills damage. Even at slightly elevated ammonia levels fish may experience a reduction in hatching success; reduction in growth rate and morphological development; and injury to gill tissue, liver, and kidneys and hyperplasia where the gill filaments are swollen and clumped together, reducing the fish's ability to take up oxygen.

Aquaculture tanks with high stocking densities should be checked daily for ammonia. Fish produce ammonia in their solid waste and excrete it through their gills.

Water used from bores needs to be checked for ammonia, and pH. If the pH is low, probably there is Co2 present. Degas the water for a short time and check the pH again. If the pH has gone up, then it is most probable that the groundwater has high Co2. It probably also has high ammonia. Cycle the water through a good bio filter and check the ammonia and Co2 again. They should stabilize over a short time. The time depends on the filters ability to break down the ammonia. A good filter will do this relatively quickly.

Sources of Ammonia

Agricultural: The primary agricultural sources include accidental releases of ammonia-rich fertilizer during transport (because of vehicle accident, faulty hose connections, and human error); and livestock waste (from barnyards, feedlots, pastures, and rangeland). 

Residential and Urban: Household use of ammonia-containing cleaning products, septic systems, and  improper disposal of ammonia products may contribute. 

Atmospheric Deposition - Available data suggests nitrogen (directly and via rainfall) constitutes a large portion of total nitrogenous inputs to estuarine and marine systems and a somewhat lesser portion to freshwater systems. Ammonia in the atmosphere is derived from combustion processes such as domestic heating, burning of municipal waste, and internal-combustion engines.
More here (Members only)

Back to links

A lot more detail here

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Below is a list of links that explain various measurable water paramenters

pH simple explaination

Water hardness

Salt and your fish        More detail about Salt (Members only)

Carbon dioxide

Ammonia

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pH SIMPLE EXPLANATION

pH: Definition

pH is a measure of how acidic or alkaline water is.
The range goes from 0 to 14, with 7 being neutral.
pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates alkalinity.
pH is really a measure of the amount of free hydrogen (and hydroxyl) ions in the water.
Water that has more free hydrogen ions is acidic, whereas water that has more free hydroxyl ions is alkaline.

Since pH can be affected by chemicals in the water, pH is an important indicator of water that is changing chemically.
pH is measured in "logarithmic units".
Each number represents a 10-fold change in the acidity or alkalinity of the water.
Water with a pH of five is ten times more acidic than water having a pH of six.

Simple pH testing is done using a few drops of pH indicator. (Bromothymol blue).
The colour of the test water is compared to a colour chart as shown below.
Bromothymol blue is a chemical pH indicator that changes colour based on the acidity or alkalinity of a solution, turning yellow in acidic conditions, blue in alkaline conditions, and green in neutral conditions (around pH 7).

Litmus paper can also be used to test pH. It shows whether a substance is acidic (red) or alkaline (blue), while pH indicator shows the strength of an acid or alkali with a range of colours.

The most accurate way to measure pH is with an electronic pH meter.
These devices come in many forms, some cheap, some expensive.

.

I bought this one here. https://pureaquatics.com.au/

It comes in a sturdy case and is easy to read, and extra easy to calibrate.

pH when shipping fish

pH is a major factor when commercial quantities of fish are shipped in static water as in a bulk bin, or an airfreight box.
In these containers co2 builds up and drops the pH, which, when fish are packed at commercial densities, will cause acidosis.

pH and underground water

In Australia I know this as bore water.
I use bore water regularly, but it MUST be degassed.
In almost all circumstances bore water has zero oxygen and very high co2. It can also contain methane and hydrogen sulfide gas.
These gasses do not have an odor. 

Below bore water before degassing.

Below the same bore water after degassing. A very big difference.

If I have added fish to this tank before degassing I risk losing them. Remember they are "logarithmic units". Each number represents a 10-fold change in the acidity or alkalinity of the water. But it is not so much the pH that is of concern because Australian perch can handle big pH changes, it is actually the high CO2 that was causing the low pH that could have killed fish.

pH and water delivery pipes

Water that travels a long way in pipes can also have very low oxygen, and low pH.
Check the DO of the water as it comes out of the pipe.
If the DO is low, you will almost always also have low pH. Degassing is needed before adding to a tank of fish.

When is pH crytical

 1. When water is used for packing fish.  

2. When ammonia is present.

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CONTACT INFORMATION. Note, due to frequent international travel, phone contact and text messages may be difficult and email replies may be delayed.

This is a RAS with some water flow-through from an external water source.
Effectively a hi-bred system, partly flow-through and partly RAS.
Having water flowing into a RAS from a trusted water source will dilute the nutrient load within the system thus taking the pressure off the entire filter system. Also, assuming the water that is leaving the system comes from the main volume of water, not after any of the filtration elements, would also mean;

1. Some of the solid waste is also being removed.
2. Organic waste is being  diluted.
3. Any pheromones the fish may be adding to the water are being diluted. (This works well for silver perch grown in a RAS)

Things to be alert to are the potential to add harmful pathogens to the system. The water supply needs to be under full control.
This potential is very much increased if the water source already has any aquatic life. E.G. fish, aquatic insects or life stages of insects, birds may have access to the water, rodents or any animals that could introduce pathogens, etc.

The water source may have an unreliable or unstable quality.
For example, if it is coming from a water body that is exposed to the environment it will be affected by weather conditions.
Heavy rain may cause changes to the water quality.
Algae will also cause considerable changes to the water quality.
Any inflow or run-off entering the water source, can have a detrimental effect on the water quality.
The water quality entering the RAS from an external water source may have no oxygen or even high undesirable dissolved gasses such as hydrogen sulfide caused by decomposition of organic matter. If the water is coming from underground this is much more likely to be the case.
Even if the water is coming from a pond or river supply which, when tested at the source is good, can change dramatically when it is traveling through a pipe line.
The longer the pipe, the greater the risk.
Just injecting oxygen to the pipe will not remove undesirable gasses.
If this is the situation, placing the water into a large water tank with very strong aeration will "de-gas" the supply making it safe to add to the RAS.
The storage tank should be close to the RAS to take advantage of this process.

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FLAVOURS DESCRIBED AS EARTHY OR MUSTY

I am sure you have heard people say they don't like the taste of freshwater fish. The biggest criticism regarding the taste of freshwater fish is usually, "they have a muddy or earthy taste," or they have a "musky pond flavour." These are often called "off-flavour" in the aquaculture industry. If you are not aware, Australian freshwater fish are commercially farmed in many countries. So, what causes these flavours, and what can be done about it? It's usually because freshwater fish "drink," get their freshwater from swallowing some, but also through their gills and skin. This means they will sometimes take in any flavour influencing taints that are in the water. The science behind all of this is way too complicated to go into here, but if you really want to know check these links. NSW Government about silver perch aquacultureand World Aquaculture SocietyTo really simplify this I'll ignore all the VAST detail and just say, "this is usually caused by a couple of compounds produced by algae." Even if the water is clear, these compounds can still be present.

Below, a picture taken from the top of a hill showing 1 acre ponds in Malaysia that breed and grow jade and silver perch.

What do commercial farms do?

Consumers demand perch that have a delicate sweet flavour. Fish that have undesirable flavours are not marketable. Off-flavours in fish present no danger to consumers, but off-flavoured fish sold in the marketplace, can result in the reputation of freshwater fish having unplesent "off-flavour." While pond management can under certain circumstances, decrease the incidence of off-flavours, in most production systems the perch must be purged. Perch are held in a purging system or holding tank where they are held for about a week, depending on conditions. Fish held in very clean water will "purge" the off flavour. Clean water will eliminate off-flavours.  Also, salt (5-10 ppt) is included in the purging water to reduce stress, to prevent fungal infections and kill ectoparasites. The salt has no effect on the taste of the fish. This is based on science. Freshwater fish do not change flavour when held in salted water. They regulate the amount of salt in the tissue through a process called "osmoregulation." If you want all the complicated science click here So, when you buy silver perch, jade perch, or Murray cod at a restaurant it should taste great. If it doesn't, the farm did not purge correctly.

Here is a little more information for commercial growers.

What can you do?

You have fish in your dam and you want to enjoy the eating quality after all the time spent waiting for them to grow. Catch and try one fish. If the water is very clear, the fish will probably taste good, if it doesn't, you can purge them yourself if you have a tank with water that you can keep clean. If you can't purge yourself, then try another fish after some time has passed. Sometimes you might just have to wait longer. Eventually the fish will have the perfect taste. Now is the time to catch a few and freeze some for later. But don't forget to eat one NOW !

For the commercial operator 

When I supply F1 fry, I guarantee they are F1, I also provide the collection location where the individual fish were captured, and the date they were captured. I also provide the individual micro chip numbers of each fish that was used to produce the fry I supply. You can trust me to be supplying genuine F1 because I will provide all these details.

F1 fry are available for jade perch. Minimum order 10,000 tails. au$1.15 each.

BELOW Collecting jade perch in 2024 at the Barcoo river.

What are F1 fish used for?

In my case, I take a wild fish, and a line bred fish, that has been selectively bred for generations, then spawn them. F1 fish should be grown and conditioned for breeding with your line bred fish..

Use the F1 fish to reinvigorate the gens of your existing breeders. Breeding F1 to F1 defeats the purpose of linebreeding. Also, the fish you received as F1 are probably brothers and sisters, so it would be bad practice to breed F1 over F1. If you have received two shipments of F1 fish this should be OK, provided the microchip numbers are different, and you grew each batch separately. In this case having me provide you with microchip numbers is a real advantage. You can order a special batch of F1 fry and ask me to use different fish to your first batch. Easily done when you tell me the microchip numbers of the first batch, so I can choose different breeders.

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GOLDEN PERCH FOR AQUACULTURE

Golden perch are a good species for aquaculture in some circumstances.

Other names for these species, in Australia are yellow belly, and callop.

This video is the species from the Lake Eyre Basin. These are wild fish caught in the Barcoo River under governmant permit. They are to be used as breeders for the supply of fingerlings to commercial fiah farms.

Most important is the understanding that there are three species of golden perch, but only ONE is suitable for aquaculture. The species from the Lake eyre Basin is the only one that research done by the Queensland Government indicated that this species is suitable. The other two species are slow growers and are not commercially viable because they are quite slow growing.

THE THREE SPECIES

Macquaria ambigua ambigua, Murray Darling River Basin

Macquaria ambigua oriens, Fitzroy Dawson river Basins

Macquaria Sp.(Undescribed)

The Lake Eyre species is relatively easy to wean to dry aquaculture pellets.

More information can be found here.

My fish will already be weaned when I send them to you.

CULTURE METHOD

This fish is not suitable for open pond culture. It is ideal for RAS (Recirculation Aquaculture System), cages, or raceways. These fish need to be crowded so they can not become terratorial. This will supress their natural predatiry behavour.

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WATER CHEMISTRY DEFINITIONS FOR USE IN AQUACULTURE

Managing the chemistry and quality of water used for aquaculture can have an enormous effect on the well-being of fish, and therefore the productivity of ponds. The following definitions and explanations are supplied to help understand more fully, some of the terminology used in aquaculture.

Total Hardness / General Hardness (GH) Short Definition: Dissolved calcium and magnesium.

Explanation

Total Hardness is a measurement of both permanent & temporary hardness; i.e. compounds of calcium and magnesium, including bicarbonates and carbonates, expressed as calcium carbonate in mg/L. A few other ions add to water hardness, but they are usually not present in significant quantities. Hard water can be recognised by the difficulty of getting soap to lather. In aquaculture, hardness levels can have a significant effect on hatch rates, growth, and overall well-being of fishes. Fish can absorb calcium, which is essential for growth, directly from the water. Total hardness is frequently referred to as General Hardness (GH) in aquarium literature, and on test kit labels. Total hardness test kits usually measure hardness in parts per million (ppm), which for our purpose, is essentially equal to milligrams per litre (mg/L). European test kits generally measure hardness in German degrees of hardness (dH). Each German degree is equivalent to 17.9ppm

Total hardness levels of between 20-300ppm are considered acceptable for pond fish culture, but many species can tolerate levels well in excess of this.

Temporary Hardness / Carbonate Hardness (KH) Short Definition: Carbonates and bicarbonates of calcium and magnesium.

Explanation:

Temporary Hardness is the same as Carbonate Hardness (KH). It is that part of total hardness that is caused by calcium and magnesium being dissolved by carbonic acid (carbon dioxide in water); in other words carbonates and bicarbonates of calcium and magnesium. These compounds are the most common cause of alkalinity in natural waters. Water with a high KH is considered strongly buffered and resists becoming acid. A good example of temporary hardness is seen in the common problem of “scale” in water pipes, hot water services, and kettles, in hard water areas. This “scale” is a direct result of calcium and magnesium salts precipitating out of solution as carbon dioxide levels drop, usually as a result of water being heated.

Aquatic plants utilize dissolved carbon dioxide as their primary source of carbon during photosynthesis. Once the dissolved carbon dioxide has been used up, carbonates and bicarbonates become the source of carbon. At night and on cloudy days the process is reversed as plants produce carbon dioxide and the carbonate and bicarbonate balance is restored. This process of using and generating carbon dioxide causes the pH of water to fluctuate, however under most circumstances the presence of temporary hardness will moderate the severity of the pH swings. (See “use of lime” below) 

KH or alkalinity test kits usually give a good indication of carbonate hardness levels (see below for details)

Temporary hardness / carbonate hardness levels of between 20-200ppm (even up to 300ppm) are considered acceptable for pond fish culture.

Potential problem with KH test kits.

Most KH test kits actually measure total alkalinity, of which KH is only a part. These kits use an acid to titrate alkalinity in water samples; this measures the waters capacity to neutralize acid. Alkalinity is usually similar to KH because the majority of alkalinity in natural waters is caused by carbonate hardness. But it is possible to have water with a high alkalinity that contains little or no carbonate hardness. For example, if one adds an alkaline phosphate to water as a buffer, the alkalinity increases and the KH test kit will give you a higher reading, but the true KH (temporary or carbonate hardness) will not have increased. KH test kits are still a very valuable tool, but it’s important to remember they measure total alkalinity, and really should be labelled this way. Many people rely on establishing the carbon dioxide level of water by using the commonly available table showing the relationship between pH, KH, and carbon dioxide. As explained previously, if “basic salts” (hydroxides), other than carbonates and bicarbonates of calcium and magnesium are present, the true KH can’t be established using a normal (KH) alkalinity test, and therefore the carbon dioxide values, as shown on the chart, become inaccurate.

Temporary Hardness (true KH) can be accurately measured by the following method.

1/ Measure Total Hardness (GH)

2/ Then boil the original sample for 5 to 10 minutes (boil sufficient water so a large proportion does not evaporate). Cover tightly so as to exclude carbon dioxide from the air, and allow sample to cool.

3/ Allow any precipitation to settle (or filter it out).

4/ Measure GH again. (This second measurement is the Permanent Hardness)

5/ Subtract the second reading from the first (Permanent Hardness minus Total Hardness) = Temporary Hardness (true KH)

Permanent Hardness Short Definition: Salts of calcium and magnesium, other than carbonates and bicarbonates.

Explanation:

Permanent hardness is also referred to as non-carbonate hardness; it is the salts of calcium and magnesium that cannot be removed from a solution by boiling. As explained previously, a few other ions add to water hardness, but are usually in insignificant quantities. Permanent hardness of water is ascertained by boiling the sample as described in steps 2, 3, & 4 above. It is the Hardness or GH reading, taken after boiling.

Measuring permanent hardness of aquaculture water is normally un-necessary, but is mentioned here for completeness.

Alkalinity / Buffering Capacity Short Definition: The capacity of water to neutralize acid.

Explanation:

Water with a high alkalinity is likely to contain ions of bicarbonates, carbonates and hydroxides. It has a strong buffering capacity, and is much less likely to undergo sudden pH drops or violent pH fluctuations. On the other hand, it is difficult to lower the pH of large volumes of such water if the need arises (although it can be done using strong acids). That part of alkalinity that is made up of carbonate and bicarbonate salts of calcium and magnesium, is known as temporary hardness, or true carbonate hardness (KH), as determined by the boiled water method described above. Dissolved carbon dioxide will cause pH of water to drop, but the alkalinity / KH will remain the same. Alkalinity (or a KH reading) is one of the most important water quality parameters to measure as it shows the underlying alkalinity of water, excluding the effect of carbon dioxide. In other words, pH will drop as carbon dioxide increases, but alkalinity (KH) reading remains relatively constant.

Expelling the carbon dioxide, say through aeration, will allow the pH to rise, returning to its starting point. If substantial quantities of aquatic plants and algae are present, water with a high alkalinity but low temporary hardness, is likely to become dangerously alkaline during periods of high photosynthesis (carbon dioxide removal by algae and plants). See note on use of lime below.

Alkalinity is determined by a test involving acid titration (the method employed in most KH test kits). The units of measurement are parts per million (ppm), or milli-equivalents per litre (meq/L). One meq/L = 50ppm. Alkalinity levels of 20-300ppm are considered acceptable for pond fish culture.

pH Short definition: A measurement of how strongly acid or basic (alkaline) water is.

Explanation:

pH is measured on a logarithmic scale of 0 to 14, with the centre point 7.0 considered neutral. For every decrease of one degree, the acidity increases ten fold. E.g. a pH of 5.0 is ten times more acid than pH 6.0 Water in aquaculture systems, if not sufficiently buffered, will tend to become acid as a result of biological processes. Water with a high alkalinity or high KH will naturally tend to be basic, and resist becoming acid. See notes on alkalinity / KH above, and use of lime below. The pH of ponds is usually lower in the morning, due to increased carbon dioxide levels, and higher late in the day, due to uptake of carbon dioxide by plants and algae.

pH can be tested using simple aquarium test kits, dip and read test strips, or electronic testers or meters. (Electronic meters must be calibrated regularly). Fish kept at a pH of less than 6 and over 9, are likely to be stressed, grow more slowly, and be susceptible to disease.

USE OF LIME

Agricultural lime, which is mostly calcium carbonate, is highly recommended for use in earth ponds where pH is low (below 6) and alkalinity is low, under 20 or even 40ppm.The solubility of calcium carbonate increases as the pH decreases. Liming raises low pH levels, and minimises dangerously high pH spikes due to plant material removing carbon dioxide during photosynthesis in waters of low temporary hardness. Under the above mentioned conditions, if for example sodium bicarbonate is used as a buffer, the pH may rise to dangerous levels of 11 or more. Generally, lime should be used for earth ponds, and shell grit or coral rubble for tanks. The use of lime (and fertilizers) has been shown to substantially increase productivity of ponds with low alkalinity. Ammonia becomes more toxic in alkaline water, and this needs to be considered before fertilizers are added, or any changes are made to pH. Detailed instructions on liming and fertilizing are beyond the scope of this article, and the reader is recommended to refer to appropriate literature.

Total Dissolved Solids (TDS) & Osmoregulation

Short definitions: TDS is a measurement of all mineral substances that have dissolved in water. (Sometimes referred to as ionic strength).

Osmoregulation is the physiological process that maintains the proper balance of salts between the inside of the fish and the water it is living in.

Explanation:

Most fish cannot survive for long in distilled water, and most freshwater fish cannot live in sea water. Between these extremes we see that fresh water fish have a variable tolerance for dissolved minerals. Therefore keeping fish in water of the appropriate TDS level for the species, will minimise effort required by the fish to osmoregulate, and therefore minimise stress. In waters of low ionic strength, the addition of sodium chloride (common salt) has been commonly used for quickly and safely raising TDS for holding, treating, and transporting fish. Testing TDS, (sometimes measured as conductivity) is the only practical method for quickly and efficiently getting a good indication of the level of all salts and minerals dissolved in water. This is an extremely useful test, and electronic TDS testers or meters, are usually very reliable, economical, and easy to use. As with all electronic testing equipment, they need to be calibrated as specified.

TDS levels ranging between 100 and 2000ppm are considered suitable for grow out, and most aquaculture applications, but many species can be cultured at levels much higher than these.

Oxygen (O2) or Dissolved Oxygen (DO) Short definition: Oxygen sustains all aerobic life, and its availability is a critical factor in aquaculture.

Explanation:

Oxygen, which makes up 20.9% of air, diffuses slowly from the atmosphere into water. Agitating the water and creating ripples at the surface by means of aeration or paddle wheels is a proven method of increasing dissolved oxygen and expelling carbon dioxide. Plants and algae also contribute to oxygen levels during daylight hours due to photosynthesis. But plants also respire, consuming oxygen and producing carbon dioxide, which can adversely affect ponds at night. For every 1 gram of oxygen consumed by fish, 1.4 grams of carbon dioxide is produced. To sustain fish life, sufficient oxygen must be available in the water at all times, to enter the fishes’ blood through the gills. Fish held at low oxygen levels have been shown to be more susceptible to disease, feed less, and grow more slowly. Low oxygen may be experienced from some underground water sources, under overcrowded conditions, in a polluted environment, after an algae crash, during hot or still and cloudy weather (particularly at night) and during transportation.

Dissolved oxygen levels can be measured on site, using chemical test kits, but using the more expensive electronic oxygen meters, is considered a better method. Fish gasping at the surface often indicates oxygen depletion.

The solubility of oxygen reduces as temperature of water rises and salinity increases. Seawater contains approximately 25% less oxygen than freshwater.

Oxygen levels in pure water at saturation are about 11ppm at 10 degrees C, and 8ppm at 25 degrees C. Levels approaching 4ppm are considered stressful, and between 4 and 0ppm deadly. (Depending on the species.) For normal health and growth, oxygen levels should be kept above 5ppm, and preferably close to saturation.

Biological Oxygen Demand (BOD)

Biological oxygen demand measurements are generally used to ascertain the degree of water pollution. BOD is a measurement of how much oxygen is consumed in a given water sample, held at 20 degrees C over a fixed time. This test is normally carried out by specialised water testing laboratories. High BOD indicates high levels of waste biological products (organics) e.g. high levels of bacteria, algae, zooplankton etc. BOD measurements are not often used by fish farmers. Knowing the oxygen level, and what percentage that is of saturation, is much more useful information.

Carbon dioxide (CO2) Short definition:

Carbon dioxide accumulates in water as a result of respiration by aerobic life.

Explanation:

When fish respire, carbon dioxide leaves the blood and enters the water through the gills. It then accumulates, or is taken up by plants and algae (by photosynthesis during daylight hours), or expelled at the water / air, interface. Aeration, (agitating the water) helps expel dissolved carbon dioxide into the atmosphere. Because dissolved carbon dioxide competes with oxygen for space in fishes’ blood, CO2 levels of 20-30ppm reduce the oxygen carrying capacity of fish blood by up to 50%.

Dissolved carbon dioxide forms carbonic acid and in un-buffered water can reach a pH as low as 4.5. As previously mentioned, water with high carbonate hardness is considered well buffered, and is less likely to undergo dramatic pH swings. High or toxic concentrations of free carbon dioxide are seldom found in alkaline surface water (above pH 7.0). Carbon dioxide is neutralized in the presence of bicarbonates or carbonates and is then not toxic to fish. Bicarbonates and carbonates act as a “carbon dioxide storage unit”. In daylight, plants take up the stored carbon dioxide and at night it is replaced, due to the respiration of fish, plants, and other aquatic life.

Carbon dioxide may reach dangerous levels in underground or bore water, in heavily stocked acid water, in transport water, and at night or on cloudy days in ponds with high levels of algae or aquatic plants. Decomposing organic matter (i.e. algae crash) is another major source of CO2 in ponds and aquaria.

Free carbon dioxide can be measured using chemical test kits, or can be ascertained from the commonly available chart showing the relationship between carbonate hardness, pH, and carbon dioxide. (If the KH is high, and the pH is low, carbon dioxide is usually high)

Carbon dioxide levels above 40-50ppm are considered dangerous, particularly if oxygen levels are low.

Lots more to learn

This is by no means an exhaustive list of terms used in aquaculture. Fish farmers can gain enormous benefits by understanding the environment our aquatic life inhabits. Knowing when, and how to alter just one or two factors, can swing a farm from struggling to success, in merely a season or two.

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FOOD FOR PERCH   

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How to Handle Larvae

Apart from being physically delicate the larvae are actually quite robust. They will tolerate very low dissolved oxygen, (DO), a wide PH range, are also tolerant to relatively sudden temperature variation, within reason. The larvae will die if you use nets. They will also die if they are shaken, such as rough road or dropped box.

Do NOT use nets to transfer the larvae. I have tested many methods of transferring larvae with nets and all but one failed. The one successful method could not be repeated!

On arrival, the packing water will have high dissolved oxygen. It is important that the oxygen level be reduced to "normal" slowly. The tried and proven method is to open the bags, and, from the tank or pond you intend to release the larvae into, gradually add your water over a period of about half an hour until the water you have added is about four times the amount of water they are packed in. Your pond or tank water should have a dissolved oxygen, (DO) level of at least 8ppm. While doing this monitor the oxygen in the bags to watch that it does not drop too low. Once the DO is about the same as your water, add the bag of water with the larvae to your tank or pond. Do not pour the larvae. You can scoop the water and larvae from the bags and lower the scoop into the tank or pond but you must not pour the larvae. You can also lower the bag into the tank or pond and carefully, “slip” the bag out of the water. Once again do not pour the water with the larvae from the bags. The temperature in your pond or tank  should be within 3 degrees Celsius.

I am often asked how to raise Jade Perch or Silver Perch larvae?

Hatcheries in Australia raise larvae of many species of freshwater fish in plankton ponds. Larvae are introduced the into plankton ponds about three or four days after they hatch. Recently I developed methods for tank rearing perch larvae.

Eggs usually take about 24 hours to hatch. I place our larvae in a tank in a dark room and shine a light in one side of the tank, if they all go to the light, this is when we put them in a large pond, we call a plankton pond. They should be attracted to light at day 3 and ready for food by day 4. This will change when the temperatures are higher or lower. Once they are attracted to light they can avoid predators in the pond. The pond is dried and then filled before the larvae are placed in the pond. This way there is plenty of zooplankton and not too many predators. I reduce the predators by passing the water through a 300 micron screen when filling the pond. Depending on temperature I fill the pond 1-2 days before I introduce the larvae.

It is widely accepted that fresh water rotifer is most probably their preferred first food. I use a half acre to one acre ponds, about 2 to 3 ML,  which I fertilize and stock with 300,000 to 500,000 larvae. The industry average return of fry from a plankton pond is abou 30% Sometimes I get up to 200,000 fry back, sometimes as low as 80,000. Perch fingerlings are weaned in ponds. From about day 10-14 I start feeding our fingerling ponds with a commercial feed in dust form. At this stage they are about 10mm long. By about day 20-25 most of the fry are feeding at the surface. By now they are about 20mm It takes 6 to 10 weeks to grow the larvae to 4-5cm. They are fed twice daily until they are ready to harvest. The food contains about 52% crude protein, 12% crude fat, and 1.6% crude fiber.

Silver perch and Jade perch larvae are AUD$0.112 each, with a minimum purchase of 300,000.

Golden perch F1 larvae (Lake Eyre species.) $0.145 cents each. Minimum purchase 50,000.

WARNING - This product is recommended for skilled commercial operators only.

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SO, YOU WANT TO BE A FISH FARMER Your Water is Worth More Than You Think !

Read this page first, then see this link about the members area.

I once had a visit from the Israeli aquaculture department. He was looking at the Australian aquaculture industry. During his visit to my fish hatchery in Queensland, he made the comment that, “Australia does so little with so much.” By that he meant that we did not use our precious water to its fullest potential.

In a country like Israel water is liquid gold. They can’t afford the luxury of only using their water resources once. Your water is worth more than you thought. You can easily use the water from your fishponds or tanks to grow vegetables. Whether you need to use your water more than once, or not, there are still questions to be asked. 

• There are several Australian freshwater fish that are ideal species for aquaculture. What fish is best for your situation? 

• Do you realise that you are starting a business? Many people have entered aquaculture without realising they are starting a business. It’s not just a “side line”, it’s a business on its own. You need to consider; do you have the time to manage another business on top of your existing agricultural activities?

• Do you have the necessary skills to grow fish? Probably not, but they can be learned. Do you have the time and commitment to learn a new skill?

Let’s look at each question, so you have an idea if you have what it takes to become, a fish farmer. 

Factors to consider. Which fish should you choose, the culture method and the climate in your area?

There are three main ways to grow fish, extensively in ponds, or intensively in ponds, or highly intensively in tanks. Extensively in ponds means no feeding, or very little feeding with very low stocking density. The number of fish in the pond is so low that it is unlikely that the fish will have any affect on the water quality. This is much like nature. A lake or river has a natural number of fish that can survive under normal conditions. There is little risk that fish can die.

Intensively in ponds, means the fish are fed regularly, and the water is usually aerated to keep the oxygen at opium levels for fish growth. The water quality is managed to keep the fish in suitable conditions to grow at a commercial rate. There is a higher risk that fish can die.

Intensively in tanks, means the fish are kept and grown in a recirculating aquaculture system (RAS) designed to handle high stocking densities, and high feeding rates. Most water quality parameters are constantly monitored. The water is filtered through sophisticated systems. Oxygen is often directly injected into the water. There is much higher risk that fish can die. If your climate does not suit the fish species you must be able to manage the conditions to suit the fish. This can only be done economically in tanks, in an insulated shed, using a Recirculating Aquaculture System, or RAS. In a RAS you are able to control the fish’s environment completely, from the temperature to the oxygen level in the water. A RAS is expensive to set up, and expensive to operate, but it does allow you to culture a very large number of fish in a relatively small area. A RAS should only be chosen if you really know what you are doing. They are highly technical and unforgiving, both biologically and financially. A RAS is ideal for growing, eels, Murray cod, barramundi, jade perch, golden perch (only the strain from the Lake Eyre Basin) and sleepy cod. There may be a few other species, which could also prove suitable for production in a RAS, but the species listed above have already proven themselves. (Only Australian native freshwater fish are listed.)

The other method of production is in ponds. Pond production is more forgiving and generally cheaper to operate. They are also much cheaper to build. The limiting factor is your climate. The species you choose to grow must be suitable for your climate. For cooler climates, silver perch are best. For warm climates, jade perch or silver perch. For tropical climates, jade perch or barramundi. Even silver perch can be grown in a tropical climate in some circumstances. Murray cod are a species that prefer cooler climates and crowded conditions. Crowding is necessary because this species is territorial. When crowded they can’t form territories. These factors make Murray cod a better species for a RAS.

Choosing to enter into aquaculture is choosing to open a new business. It’s not a “side line” or a hobby. In most jurisdictions you will need to get a permit or licence to grow fish commercially. In all situations you will need to know how to produce a good quality product and most important, how to market your product. A poor-quality product will not get you a good price, and you will soon gain a bad reputation.

Consistent supply is also important. Customers need to know they can count on your ability to provide product throughout the year. Also you will need to know how to get your product ready for market. Fish need to be “market prepared.” Fresh water fish can have a muddy, or musky flavour if not properly prepared for market. This is known as “off flavour” or pond flavour. Professional fish farmers know how to prepare their fish so they don’t have “off flavour.”

You will need a purging system, appropriate harvesting equipment, water testing equipment, and a suitable supply of quality water. You probably won’t already know how to keep fish and grow them efficiently, and profitably. Learning how to do this is essential. There are many ways to do this. You could employ a manager to run your fishy business who already has the experience needed. You can also talk to people who are already in the finfish business, but whatever you do, don’t start to build your fish business until you have studied the subject thoroughly. You can start right here on this website.  YouTube is also a good source of information. For example the jadeperchman channel has three levels of information. There are many free videos, as well as two levels of pay to view content. See these webpages for details.

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  Site last updated January 15th 2026

This website containes knowledge gained over almost 40 years.

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This information is part of a paper by, John Hargreaves and Martin Brunson, Mississippi State University. It has sound information about CO2, (carbon dioxide). Every fish farmer should have at least a basic understanding of CO2 and how it can affect their fish pond.

The primary sources of carbon dioxide in fish ponds are derived from respiration by fish and the microscopic plants and animals that comprise the fish pond biota. Decomposition of organic matter is also a major source of carbon dioxide in fish ponds. While producers are rightly concerned with maintaining adequate concentrations of dissolved oxygen, knowledge of the “flip-side” of the oxygen equation is also important.

Fish ponds can be thought of as “breathing” over a 24-hour period. During the day, when the sun is shining brightly, oxygen is supplied to the pond by photosynthesis of algae and other aquatic plants (the “inhale”). During the night, photosynthesis ceases, and the algae, sediment and fish consume oxygen (the “exhale”), producing the characteristic fluctuating pattern of dissolved oxygen concentration well known to fish farmers. The daily pattern of carbon dioxide concentration is generally opposite that of dissolved oxygen. During the day, algae take up or “fix” carbon dioxide that is free in the water and carbon dioxide concentration is therefore lowest (often 0 mg/L) during late afternoon, when dissolved oxygen is highest. During the night, the respiration of pond organisms produces carbon dioxide, which accumulates to a maximum (usually around 10 to 15 mg/L) at dawn.

The problem with the potential toxicity of carbon dioxide can be related to the daily fluctuating pattern of dissolved oxygen and carbon dioxide concentrations. Carbon dioxide concentrations are highest when dissolved oxygen concentrations are lowest. Thus, dawn is a critical time for evaluating pond water quality from the standpoint of both dissolved oxygen and, to a lesser extent, carbon dioxide. In addition, there is some evidence to suggest that the toxicity of carbon dioxide is enhanced by low dissolved oxygen concentrations. Fish are able to rid themselves of carbon dioxide through the gills in response to a difference in carbon dioxide concentration between fish blood and the surrounding water. If environmental carbon dioxide concentrations are high, the fish will have difficulty reducing internal carbon dioxide concentrations, resulting in accumulation in fish blood. This accumulation inhibits the ability of hemoglobin, the oxygencarrying molecule in fish blood, to bind oxygen, and may cause the fish to feel stress similar to suffocation.

The density of the algae bloom has an important effect on the magnitude of daily fluctuations of oxygen and carbon dioxide. Oxygen and carbon dioxide concentrations in ponds with a light algae bloom will not fluctuate very much between early morning and late afternoon, analogous to “shallow breathing.” In ponds with a thick, dense algae bloom, fluctuations are more extreme, analogous to “deep breathing.” Carbon dioxide problems are therefore more likely as the thickness of the bloom increases.

Carbon dioxide problems most likely in summer

Over an annual cycle, carbon dioxide concentrations are maximum during winter and minimum during summer. However, carbon dioxide is rarely a problem in winter because dissolved oxygen concentrations are usually well above saturation levels. Occasionally during the winter fish may appear to swim listlessly near the surface as if they were “under the influence,” possibly due to elevated carbon dioxide levels. Such a condition may arise after a period of extremely calm and cloudy weather, but quickly passes once sunny or windy weather returns. Summer is the time of year when carbon dioxide is most likely to be a problem in fish ponds. Warm water temperatures increase the metabolism of all pond organisms and therefore respiration rates are high. It is also a time of year when feeding rates are high. The decomposition of wastes generated by large quantities of organic matter added to fish ponds in the summer requires large quantities of dissolved oxygen and produces arge quantities of carbon dioxide. During the summer, carbon dioxide concentrations are lower than during winter, but dissolved oxygen concentrations are often critically low. Fortunately, summer is also the time of year when ponds are aerated frequently. In addition to supplying critical dissolved oxygen, vigorous aeration will drive off some proportion of the carbon dioxide produced in the pond.

Measure pH to estimate carbon dioxide

Carbon dioxide can be measured directly with standard test kits. Alternatively, measurement of pH can be used to estimate carbon dioxide concentration because carbon dioxide acts as an acid in water. As carbon dioxide is added during the night, pH will decline. (Conversely, when carbon dioxide is removed during the day, pH will increase.) There are important interrelationships between carbon dioxide, pH and total alkalinity. Knowing pH and total alkalinity will allow the estimation of carbon dioxide. Estimation of carbon dioxide by pH measurements is plagued by difficulty in obtaining an accurate pH measurement. Litmus paper, drop counting test kits, and various probes with meters have been used with varying success. The selection of measurement devices for pH is largely a situation in which “you get what you pay for.” For example, pH pens are inaccurate, particularly if not calibrated correctly, and do not compensate for changes in temperature. Some scientific supply houses now sell narrow-range litmus paper which allows for low-cost, rapid estimation of pH.

Graphical estimation technique is easy

The first step is to determine the total alkalinity of the pond water using a standard test kit. Next, determine the pH from a water sample collected without splashing or bubbles. Draw a straight line up from the pH value to the curved line representing the total alkalinity value closest to that of the pond (Step 1). Now extend another straight line to the left hand axis, indicating the free carbon dioxide concentration (Step 2). The straight line extending across from 20 mg/L represents a “critical” concentration, above which carbon dioxide may be a problem. Therefore, using the chart, a set of “critical” pH values can be determined for ponds with different total alkalinity. In general, water can hold more carbon dioxide as temperature declines, although differences in temperature are less important than differences in total alkalinity and thus, for practical purposes, application of some kind of temperature correction is not necessary for estimation of carbon dioxide. However, alkalinity provides “buffering capacity” to pH changes caused by carbon dioxide and pH is therefore unlikely to fall to such critical levels. The pH of most ponds at dawn is usually between 7.5-8. Carbon dioxide in ponds with low alkalinity (20 to 50 mg/L as CaCO3) may cause the pH to fall to the lower limits of the range for optimum fish growth and production. The potential for carbon dioxide problems can be evaluated by a simple, “quick-and-dirty” method. Collect a bucket of water and measure the pH. Put an airstone in the bucket and run air through the water for about 30 minutes. If the pH increases by more than one pH unit, then carbon dioxide may be a problem.

Carbon dioxide is an unusual problem in fish ponds

In general terms, carbon dioxide is rarely a cause for concern in fish ponds with sufficient alkalinity.

There are a few specific circumstances or scenarios in which carbon dioxide may be a problem, such as the period following the crash of an algae bloom or the application of an algicide, such as copper sulfate. Large quantities of organic material derived from dead plankton are quickly decomposed, reducing oxygen and increasing carbon dioxide. Again, emergency aeration practices serve the dual role of supplying oxygen and reducing carbon dioxide. Under certain circumstances, carbon dioxide can be a problem in ponds deeper than 4 or 5 feet. Deep ponds may “stratify” or develop layers of relatively lighter, warmer, oxygen-rich water overlaying layers of relatively more dense, cooler, stagnant (and carbon dioxide rich!) water. In ponds that have not been aerated or mixed for several weeks during warm and relatively calm weather, strong sustained winds or vigorous aeration can cause ponds to “roll over” and mix deep water with surface water, thereby increasing carbon dioxide concentration throughout the water column. During the summer, when carbon dioxide is most likely to be a problem, ponds are typically aerated through the night. Although deep ponds may stratify and destratify daily, water currents established by aeration and wind blowing over the water surface usually keep the water column well-mixed and, as a result, carbon dioxide problems rarely occur.

Carbon dioxide may accumulate when fish are held at high density, such as in hauling tanks or crowded in front of aerators during low oxygen episodes. Even though carbon dioxide levels may rise dramatically, the problem can usually be alleviated by aeration, which adds oxygen while driving off some carbon dioxide.

Chemical treatment is a temporary solution

Carbon dioxide can be removed by chemical treatment of pond water with liming agents such as quicklime, hydrated lime or sodium carbonate. These liming agents chemically react directly with carbon dioxide, resulting in reduced carbon dioxide and increased alkalinity and pH. Agricultural lime will not chemically remove carbon dioxide from pond waters.

In order to calculate the amount of a particular liming agent to apply to a pond, the following generalized formula can be used. 

x carbon dioxide concentration (mg/L)

x pond area (acres)

x average depth (ft)

= pounds of liming agent to add

For example, the amount of hydrated lime required to treat a 10-acre pond with an average depth of 4 feet and a carbon dioxide concentration of 20 mg/L is 3.45 x 20 x 10 x 4 = 2,760 pounds or approximately 1.4 tons. Treatment of the same pond with sodium carbonate would require 5,184 pounds or 2.6 tons. Clearly, large quantities of liming materials are required to chemically treat a carbon dioxide problem.  

At best, treatment with liming agents represents a temporary solution. Once carbon dioxide is consumed by reaction with liming agents, additional carbon dioxide may accumulate because treatment of ponds with liming agents does not address the root cause of a presumed carbon dioxide problem. In ponds receiving feed at very high rates (>100 lbs/acre per day) or in which rapid decomposition occurs following an algae crash, treatment with a liming agent does not affect the rate of carbon dioxide production and thus represents a temporary, “band-aid” solution.

Perhaps a more serious consequence of chemical treatment of carbon dioxide problems is related to pH, which may exceed 10 in poorly buffered (low alkalinity) waters following treatment with certain liming agents (such as quicklime and hydrated lime). High pH causes a shift towards a greater proportion of the more toxic form of ammonia. Consequently, a well intended application of certain liming agents to “treat” what is thought to be a carbon dioxide problem can result in a very stressful environment for fish.

The bottom line

Application of chemicals to treat a carbon dioxide “problem” is likely to be of limited, temporary benefit. Aeration and mixing are the most effective available mechanical methods for the management of carbon dioxide and dissolved oxygen. Vigorous aeration accelerates the diffusion of carbon dioxide out of water and mixing will prevent or minimize the establishment of a carbon dioxide-rich layer of water near the pond bottom. Maintaining a moderate plankton density (Secchi disk visibility between 6-12”) will maximize the biological uptake of carbon dioxide.

A clear determination of a carbon dioxide problem is required prior to any treatment. If a carbon dioxide problem is suspected, other water quality variables (particularly dissolved oxygen and ammonia) should be evaluated before attempting any treatment.

The toxicity of carbon dioxide increases as dissolved oxygen concentration declines. Often, the problem can be traced to something other than carbon dioxide.

Link to PDF of the full paper.

The PERCH MAN

SILVER PERCH

More about silver perch

CATFISH

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AUSTRALIAN BASS 

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GOLDEN PERCH

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BARRAMUNDI

Pictured above, Tony Sambell with a great barra he caught in our farm dam many years ago.

Barramundi is an Aboriginal word meaning large-scaled river fish.
They can grow to well over 40 kilo.

SARATOGA

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Fingerling price list at bottom of page. to order, email: This email address is being protected from spambots. You need JavaScript enabled to view it. 

How many fish can I stock ?

What a question! There is not a simple answer.

Firstly lets break this question down into sub-questions.

What are your intentions?

For a farm dam. Farm dams are not the same a a commercial pond.

The stocking rate is calculated from surface area alone, ignoring depth and volume. Within reason. Generally, the fish need water depth to range between half a meter to one and a half meters. This will give the fish a range of habitats to use under different conditions. Stock at one fish for every two meters of the distance around the dam. (The perimeter)

To create a place to go fishing

To be able to catch fish very easily stock silver perch at a minimum of 300 per acre, or about 700 to 800 per HA. You will probably need to feed them eventually as they grow.

To reduce the amount of weed in a dam

Fish can’t stop the water from turning green. (Green water.) Australian perch will eat filamentous algae, but sometimes that will still grow faster than the fish can eat it. If you are not too concerned about being able to catch them, just stock about 100 fish per acre, or 250 per HA.

To grow fish for you to eat

You will need enough fish that catching them is not too difficult. If you stock at very low densities, they might be too hard to catch. Therefore, stock at similar densities as you would to create a great place to go fishing. Remember, you might need to feed them to get really good growth rates.

To become a commercial farm.

Firstly, you need to be aware of the laws in your area, state, or country. In Australia, each state has slightly different rules/laws. However, every state requires a level of “licencing” for a commercial fish farm. There are also laws about what species can be grown, and the structure they can be grown in. That is, an earth pond, an above ground tank, or tanks in a covered area like a shed. One thing is common in all states, you can’t sell fish without an aquaculture licence/permit.

Assuming you have all the appropriate approvals, and are growing an approved species, determining the correct stocking densities starts by stocking a “safe” number of fish, then monitoring the water parameters throughout the growing period. (Keep records so you can refer to them for the next crop.) After your first crop has been harvested you can now judge if you can increase stocking levels for your next crop. Keep in mind different species may perform differently and change the way water quality behaves.

Many species don’t have any research data that I can refer to, so here I make assumptions based on silver perch research, and personal communications with commercial growers in Australia, and clients in Asia. Silver perch have been grown commercially since 1990, and jade perch since the mid to late 90’s.

Stocking densities range considerably, depending mainly on aeration and water exchange. Stocking a .4 ha (1 acre) pond with about 20,000 fingerlings to start the growing process, then as growth performance and water quality indicate, (Mostly the ability to maintain suitable oxygen levels.) the fish numbers should be reduced. Move some of the fish into another pond, and continue to do this as the fish grow, and water quality or oxygen drops.

A commercial farm final harvest totals ranges from1.5 ton to 40 ton, depending on the pond conditions. This is based on a .4 ha pond. Ponds without any water exchange or aeration are at the low end, and ponds with aeration and high water exchange are at the top end. Keeping an eye on temperature, P.H. ammonia, and oxygen levels, especially oxygen very early in the morning, is essential to avoid poor growth rates and fish losses through disease and overstocking.

Oxygen levels should be taken just after sunrise, and just before sunset. This should be done regularly and recorded in a pond diary so they can be referred to later.

Some fish will not grow well when densely stocked. Silver perch is an example of a species that will not grow well when stocked at high densities. Not really a problem with jade perch. Regularly checking your crops growth performance is essential. A suitable number of fish should be sampled very regularly. Check weight and look for disease and parasites. USE A MICROSCOPE and reference books to identify diseases.

If your fish are not growing well and there is no disease present, you might have a crowding situation. It could also be the food. If food is not stored correctly, or it is too old, it may have lost some of its vitamins etc. Underperforming fish growth is often related to food.

The amount of food being fed must be recorded. These records can be used in the future as well as giving an indication of the FCR, (Food Conversion Rate). That is, how much food is fed to the fish to gain weight. If your fish grow 50 grams over a set time, the amount of food fed to the pond during this time, should not exceed 100 grams per fish. So, you can see, records are vital for profitability. They are also an excellent reference for you during the growing of future crops. Remember, each pond may perform slightly differently.

In summary, a commercial pond is a managed environment. The proper management, and record keeping is what determines how many fish can be stocked, and this would be determined over several crops.

Also see this page about overstocking - Kangaroo Syndrome

SILVER PERCH AND JADE PERCH PRICE LIST

Fingerlings are 4 to 5 centimetres. For export of bulk fry the size is usually 1.5 to 3.5cm.

• 30- 49 --- $2.31 
• 50- 99 --- $2.20 
• 100-500 -- $1.43 
• Over 500 --- $0.94 .
• F1 fry are available by arrangement. Minimum order 10,000 tails. $1.15 each.
• 1.5 - 3.5 cm FRY. WHOLESALE PRICES OVER 10,000 AUD$0.43 each.
• Fish food can be ordered and delivered with fingerlings.

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The PERCH MAN

To order, email: bruce@theperchman.com

HOW MANY FISH CAN I STOCK ?

What a question! There is not a simple answer.

Firstly lets break this question down into sub-questions.

What are your intentions?

For a farm dam

The stocking rate is calculated from surface area alone, ignoring depth and volume, within reason. Generally, the fish need water depth to range between half a meter to one and a half meters. Deeper water is ok, but it is mostly about the surface area of the dam. This will give the fish a range of habitats to use under different conditions. Stock at one fish for every two meters of the distance around the dam. (The perimeter)

To create a place to go fishing

To be able to catch fish very easily stock silver perch at a minimum of 300 per acre, or about 700 to 800 per HA. You will probably need to feed them eventually as they grow.

To reduce the amount of weed in a dam

Fish can’t stop the water from turning green. (Green water.) Australian perch will eat filamentous algae, but sometimes that will still grow faster than the fish can eat it. If you are not too concerned about being able to catch them, just stock about 100 fish per acre, or 250 per HA.

To grow fish for you to eat

You will need enough fish that catching them is not too difficult. If you stock at very low densities, they might be too hard to catch. Therefore, stock at similar densities as you would to create a great place to go fishing. Remember, you might need to feed them to get really good growth rates.

To become a commercial farm. 

Firstly, you need to be aware of the laws in your area, state, or country. In Australia, each state has slightly different rules/laws. However, every state requires a level of “licencing” for a commercial fish farm. There are also laws about what species can be grown, and the structure they can be grown in. That is, an earth pond, an above ground tank, or tanks in a covered area like a shed. One thing is common in all states, you can’t sell fish without an aquaculture licence/permit.

More detail for commercial ponds is in the members area of this website.

Fingerling prices are here. 

To order fish or food email bruce@theperchman.com

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The PERCH MAN ABN 42 065 149 145

To order fish, email: This email address is being protected from spambots. You need JavaScript enabled to view it. 

Note: To view full size pictures,right click picture, open in new tab.

To prevent your fish from escaping, and to prevent unwanted fish from entering your ponds, they need to be fitted with an appropriate sized overflow pipe which has an appropriate size screen. That means a screen size that will work efficiently, allowing excess water to exit the pond, without letting your cultured fish escape, or any unwanted fish species entering your pond. This pipe should be positioned correctly to be effective. 

In Australia, many native fish species will swim long distances through running water, even through very shallow water, and grass. Tilapia will also travel long distances in the same way. It is common for tilapia to be in rivers and streams in many countries. Particularly in Asia and north eastern Australia, where they have established themselves in water holes, creeks and rivers. If these fish enter an aquaculture pond they will compete with the species you are trying to grow. They will eat the aquaculture feed you use to grow your commercial crop. They will breed to plague proportions making it difficult to sustain profitability. Tilapia have a very low commercial value, especially compared to more commercial species such as jade perch.

The pipe needs to be large enough to handle the amount of water that will enter the pond during heavy rain. The surface area of the screen should also be large enough to allow all the water to freely flow fast enough to keep up with the heaviest rain. Below pipe is 150mm (6") with 50mm holes.

Drilling large holes, or cutting pieces out of the pipe will give the screen support so it does not collapse during high water flows. This is particularly necessary in the tropics where high rainfall is common.

  

The pipe should be angled so that the screen is below the water level when it overflows. This is to reduce the chances of the screen becoming blocked with leaf litter and grass. If it is at the surface it will work like a tea strainer and quickly become blocked increasing the risk of the pond overflowing its banks. The screen should also be cleaned regularly to maintain efficiency.

Rodents will also make holes which must be repaired.

The outlet should be above the ground to help reduce the chances of fish entering the pipe and finding their way into the pond, even though it has a screen, baby fish could still enter the pond.  

The outlet should be maintained and free of vegitation. Unlike the pictures below. Here the grass has not been kept away from the pipe outlet which will slow the flow of water.

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The PERCH MAN ABN 42 065 149 145

BELOW RIGHT Before anything was built knowing how tanks drain, and water could be treated is essential. BELOW LEFT The water storage dams shown here are all at the lowest point on the property. Note you can see full size images. Just right click the image and open in new tab.
BELOW The purging tanks are installed  before the  shed  is  constructed. Planning how everything is to work is essential. You need to know how the farm will work after is is built.

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The PERCH MAN ABN 42 065 149 145

co2 during transport of fry - why you must unpack correctly

During transport the co2 in the shipping water will build up dramatically. The longer the fish are in the bags, the more dangerous it will become. Eventually reaching lethal levels, if the fish were not packed using pure oxygen. Not using pure oxygen in shipping bags would be extraordinarily unprofessional. Equally, not unpacking correctly is just as unprofessional. I agree, it would be possible to bypass the time consuming process of repacking the fish upon arrival after shipping. However, many times this will result in very high losses of fry, that would be in perfect condition, if my recommended method had been used.

Related videos: https://youtu.be/epA822noyok https://youtu.be/c0u9Stf5_5o https://youtu.be/OwD2gXi7tho 

IS IT WORTH THE RISK? If they are your fish, it's your money, you decide. If it is your boss's money, see if he agrees with you after bypassing the process and experiencing high losses.

The other option is to pack much less fish in each bag thus reducing the amount of CO2 at the end of the shipping. The problem here is that there would be many more boxes of fish. Air freight is costly. Again who's money is being spent, yours or your boss? The more fish packed in a bag, the cheaper the freight. Each box has a cost, and the airlines charge by weight. Each box is about 11 kilos. Generally for about 24 hours of transit time, 500 fry are packed in a box. For 48 hours of transit time, 300 fry are packed in each box.

CO2 works like an anaesthetic which has a very considerable "positive" side. In fact there are two positave side effects. 1. The fish use less oxygen. 2. the ammonia is converted into ammonium which is relatively harmless to the fish. Whereas ammonia is deadly. This happens because the CO2 greatly reduces the PH of the water in the bag. The affect on the fish is called acidosis. See this video.

The fish have very slow respiration due to their "anesthetised" state. (This means the pure oxygen the bag is infalted with will last longer.) Slow gill movement, perhaps as low as once or twice per minute, means that each time the fish moves water over its gills, it must get as much oxygen as possible. This is why there is a need to repack the fish in higher than normal dissolved oxygen. See the video for how to get the oxygen in the new water at the right level. If you use a dissolved oxygen meter you will find that normal oxygen in water, under normal conditions, with fish, is usually less than 8 Milligrams per liter (MPL), which is the same as 8 parts per million. When you bubble pure oxygen in water it quickly reaches about 20 Milligrams per liter (MPL). Here is the key to keeping them alive and well ! At very high oxygen levels, the CO2 will not kill the fish. In fact, it acts as an anesthetic, and that actually helps the fish during transit. Because they are partially anaesthetized they use less oxygen during transit. (Note, if a bucket of water was left standing at sea level, at 25C, with no airflow across its surface, the dissolved oxygen will stabilize at about 8 Milligrams per liter (MPL).

Yellow is low. Green is safe. Red is dangerous.

What happens, after shipping, if the fish are released into water with "normal" oxygen levels? They will often have fits", swimming erratically, jerking around as the high co2 in their brain, without the presence of very high oxygen, takes its effect. Many will have seizures, sinking to the bottom with their fins extended, and their mouths and gills locked open. While some will recover, many will die. This is avoided if they are repacked correctly, using fresh water, (With no co2.) that has a very high oxygen level. This can only be achieved using pure oxygen, the way the demonstration video shows.

When and why I do or do NOT guarantee live arrival.

CLICK FOR STEP-BY-STEP INSTRUCTIONS FOR UNPACKING PDF file

See this video:  

Also see the information about salt.

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The PERCH MAN ABN 42 065 149 145

CONTACT INFORMATION. Note, due to frequent international travel, phone contact and text messages may be difficult and email replies may be delayed. Preferred contact method is by email. Phone number is for emergencys ONLY.

Whatsapp: Bruce Perch Man         

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Website:  www.theperchman.com      

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YouTube: jadeperchman       

Premium Client Videos

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Telegram:  Bruce Sambell Perch Man +61 407 797 149

Phone:  +61 407797149

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RECIPES and tips

When cooking either Jade Perch or Silver Perch, it is important not to UNDER cook. You often hear the comment "don't over cook fish as it will dry out too much."

With perch, it is the opposite. Undercooked perch will be too sloppy. It needs to be well cooked to bring out the best in it's texture. There is plenty of moisture in sweet water perch. 

Perch are very high in omega-3 oils. Much of this oil is to be found in the fat. Each fillet usually has a strip of fat along each side. If you find the flavour of the fat a bit strong, simply trim the strips of fat from the sides of the  fillet. It will cut away easily or it can be pulled away with your fingers. Some people consider the fat a delicacy and fry the fat separately. Some people even purchase omega-3 capsules from health stores, these strips of fat are extremely high in omega-3s

Trimmed perch fillets should not have any strong flavor. If it has a weedy or muddy taste, the fish have not been properly finished by the grower. You should not purchase from this grower if the problem persists. Perch have a delightfully delicate flavour, with a melt in the mouth texture. Perch are rich in healthy omega-3's.

Below are a few recepes to try

This recipe won the Aquaculture Association of Queensland 2018 cooking competition

Prep time 20 minutes. Cook time 25 minutes

Ingredients

1 kg Sushi rice
1 bottle Sushi seasoning
4 Jade Perch fillets
2 cups mirin
Japanese rice wine condiment
2 cups light soy sauce
Preferably Japanese style
1 cup Brown Sugar

Instructions
1:cook sushi rice according to packet instructions. Then add sushi seasoning and cool on flat tray. Place weights on rice to make a firm even rectangle and chill.
2: Combine mirin, soy sauce and sugar in a pan and reduce by half.
3: Carefully fillet your Jade perch remove all pin bones and de-scale.
4:Place Jade perch fillet on grill, BBQ or in frying pan. Brush sauce over fish and continue turning and brushing sauce layering more and more sauce each time the fish is turned over.
5: Cut chilled rice into small rectangles and then add lacquered fish fillets on top of sushi rice.
6: Serve with pickled ginger, soy sauce and wasabi.

This recipe won the Aquaculture Association of Queensland 2017 cooking competition.

Prep time 30 minutes.  Cook time 15 minutes.
Ingredients

 4 Jade Perch fillets
10 fl oz Chicken Stock
1/2 cup soy sauce
1/3 cup Brown sugar
1 tea spoon grated fresh ginger
1 table spoon cornflour
1 orange juice and zest

Instructions
1.  In a saucepan whisk together stock, soy, sugar, ginger, cornflour, orange juice and zest.
2. Bring to the boil, whisk lower heat and cool.
3. Place fish fillets in glaze and refrigerate for one hour.
4. Sear fish on BBQ or grill 2 minutes each side. Lower heat and cook through for a further few minutes depending on fish thickness. Be careful as glaze burns easily.
5. Pour remaining sauce into a small saucepan and boil then pour over fish and serve.

Macadamia Nut crusted Silver perch on Pineapple & Cucumber Salsa

INGREDIENTS

• 80g Silver perch fillet
• 30g Toasted & crushed macadamia  nuts
• 1 table spoon seeded mustard
• 10g melted butter
• 10g fresh breadcrumbs
• 15g diced pineapple
• 15g diced deseeded cucumber
• 5g diced capsicum
• 5g diced red onion
• 5g chopped parsley
• 5 mls olive oil
• 5 mls balsamic vinegar
• 1 lemon wedge

METHOD

Mix pineapple, cucumber

capsicum, onion, parsley, oil & vinegar.

seal off perch in a little flour, butter & oil.

After it is half cooked top with macadamia crust mix.

Place under grill till golden brown.

To serve place fish a top of salsa mix with a wedge of lemon

Silver Perch Meuniere

INGREDIENTS

• 2 fillets of silver perch
• 2 tablespoons butter
• 2 tablespoons plain flour
• ¼ cup white wine
• 1 dash lemon juice
• chopped parsley
• salt and pepper

METHOD

Fillet silver perch. Melt butter in fry pan, dust fish in plain flour, salt and pepper. Fry for 2 minutes both sides. Deglaze with white wine add lemon juice and chopped parsley just before you serve stir in butter.

Perch with mayonnais and breadcrumbs

INGREDIENTS

• Filleted fish
• Traditional mayonnaise (I use Praise or Kraft)
• Coleslaw dressing (I also use Praise or Kraft)
• Freshly made breadcrumbs
• Fresh tomatoes sliced
• Parmesan cheese optional

METHOD

Very simply in large baking dishes lay one layer of fish, spread mayonnaise over fish as if buttering bread (not sparingly), drizzle coleslaw dressing over mayonnaise, sprinkle breadcrumbs over top, place sliced tomato on top and sprinkle with parmesan cheese, repeat for the second layer.

Bake in 180 degree oven for aprox 45-60 minutes, depending upon the thickness of the fillets.

Island of Spetsai Silver Perch

INGREDIENTS

• 750 gm Silver Perch Fillets
• Lemon juiced
• 1 ½ cups Extra virgin olive oil
• 4 tablespoons Tomato Puree
• 3 tablespoons Chopped parsley
• Cloves garlic chopped finely
• About 2 cups Breadcrumbs

 METHOD

Rub fish with lemon juice and salt and let stand in fridge for ½ hr

In a bowl mix the oil, tomato puree, parsley, garlic, lemon juice and juices from fish

Place fish on bottom of baking tray – one fillet deep

Spread over the oil mix

Cover with a thick layer of breadcrumbs so that no fish is showing

Bake in pre heated oven at 180o  for about 30 mins until sauce is absorbed and fish is cooked.

Carefully divide onto individual warmed plates with a spatula.  No garnish is needed. Serve with crusty Greek bread and a Greek salad for a superb luncheon.

SERVES 4

Silver Perch Soup With Cennellini & Pistou

3 cloves garlic, chopped

• 1 cup firmly packed basil leaves
• 40g (½ cup) grated parmesan
• 1/3 cup olive oil.
• Season to taste
• 50g pine nuts

(You may purchase a basil pesto from the supermarket, instead of making Pistou to drizzle on the finished soup).

METHOD

Add drained cannellini, onion and bay leaf to a medium saucepan (if using canned Cannellini add at the end) of boiling water and simmer over medium heat for 30 minutes or until just tender. Drain and discard onion and bay leaf.

FOR PISTOU

Combine garlic, basil and parmesan and pine nuts in a food processor and process until will combined ( or pound in a mortar and pestle). Add olive oil in a thin steady stream until smooth, then season to taste. Heat olive oil in a large saucepan and cook leek over low heat until soft, add Garlic, tomato and wine and cook over high heat until tomato is reduced to a pulp. Add stock and simmer until tomato is reduced by a quarter, then season to taste. Add cannellini and green beans and simmer for 5 minutes, then add fish and simmer until cooked, ladle soup into four soup bowls and drizzle with pistou. Serve with good French Bread, if desired.

SERVES 2

Fish and chips

Ingredients

• Oil for deep frying 
• 4 boneless fillets of Silver perch
• 225g plain flour
• 225g bread crumbs
• Cool water
• 4 large potatoes for chipping.

Method

Cut fillets into portion sizes, coat with plain flour, dip into water and roll in bread crumbs.  Deep fry in oil until well cooked. Place on tray lined with absorbent paper to drain.

Peel and chip potatoes.  Deep fry in oil until cooked.  Place on tray to drain.

Return fish to oil and reheat for  a short time. Place on paper to drain.

Return Chips to oil and cook until crispy. Place on paper to drain.

Serve either as fish and chips or with a salad.

 Golden Fried Potato Coated Fish and Chips

Especially for people with Gluten Problems 

Batter

• 2 Potatoes (grated)
• 2 Eggs
• Salt to taste
• Plain flour to thicken batter  (Best with Gluten Free Flour
• Mix all together 

Fish

• 6 Fillets of Fish
• Plain Flout to coat Fillets 

Method

Grate Potatoes add egg and salt and mix to batter using the Plain Flour.

Coat Fish Fillets with Plain Flour and then with Batter mixture.

Deep Fry until golden Brown.

Serve with Lemon and Chips. 

 Sesame and Herb Fried Silver Perch on an Orange Salad with Saffron Mayo

Ingregients

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The PERCH MAN ABN 42 065 149 145

I can supply fish for mosquito larvae control. To order email This email address is being protected from spambots. You need JavaScript enabled to view it.

Larger species, such as perch, will eat mosquito larvae when they are young fish, but once they grow bigger they are not effective at reducing mosquito wrigglers. Larger fish don't hunt small prey.

Small or large quantities of the appropriate species for mosquito management for your farm dam, garden pond, local councils, mining companies, or developers. Large water bodies, such as settling ponds, water treatment storage etc. Contact the Perch Man to discuss the correct species for your requirements and region.  This email address is being protected from spambots. You need JavaScript enabled to view it.

30 - 50     ---      $2.00
51  - 100  ---      $1.75
101 - 500 ---      $1.00
501 - 5000  ---   $0.85
Over 10,000 - - - $0.40

Firetail gudgeons.  

AVAILABLE NOW At above prices

These are the easiest fish to use for mosquito management in small ponds and dams. 

Water temperature; 10°C - 30°C. They will establish a balanced population in most garden ponds, farm dams, lakes etc. Firetail gudgeons only grow to about 4-5cm and are prolific breeders in ponds and dams. Native to most parts of the north east coastal areas of Australia. You can catch your own in creeks near your location but be aware of the maximum you are permitted to catch. Bag limits may apply.  Email me to order, This email address is being protected from spambots. You need JavaScript enabled to view it.  More information here, and here

Pacific blue-eyes, Pseudomugil signifer

Not available at the moment. Advance orders considered at negotiated prices.

Blue-eyes are also an excellent way to control mosquito larvae, (wrigglers). Pacific blue-eyes are a small species only growing to about 4cm. Their favourite food is midge and mosquito wrigglers.

This species of blue-eye are native to most creeks and rivers from about Sydney to Far North Queensland. They will breed and establish a balanced population in most garden ponds and farm dams.

Rainbow fish, Melanotaenia species

Not available at the moment. Advance orders considered at negotiated prices.

Rainbows are another species that love to eat mosquito larvae.

Most streams in Northern Australia have Australian rainbows in them. The southernmost river system to contain rainbows is the Murray-Darling River Basin. Each stream has a unique colour morph. It may be a disaster to stock a pond or farm dam with the wrong colour morph. If they were to escape and breed with the local colour morph, your local colour morph could be lost forever. Below are a few examples of the different colours found in different locations. Click on the picture to enlarge.

The best way to get the right colour morph is to catch your own. BUT not a good idea where crocodiles might be. It is legal in Queensland for you to catch a small number from your local streams and stock them in your dam. The best way to find your local colour morph is to follow the down-hill fall of the land from your property to the first creek or river. If the spot you find is not suitable for collecting rainbows, check a map of your area and find yourself a site on the same creek or river that you can collect from. Choose a location as close as possible to your property. Some river systems are quite large, and may contain different colour morphs at different points.

They are easiest to catch at night. Just use a 20 ltr bucket, with about 10cm of water in the bottom. You need the 20 ltr bucket to stop them from jumping out. Add about a level teaspoon of cooking salt, (not table salt) to the water in the bucket. With a good torch, such as a "Dolphin" the rainbows are easy to spot as they drift in the eddies or near the edge of a steep bank. Use a long handled fine net. A 10 or 12 inch aquarium net is ideal. Use some plastic pipe to extend the handle, such as electrical conduit. Just squeeze the loop at the end of the handle until it slides tightly down the pipe.

Don't charge at the fish as the ripples you make or any sound on the creek bed will spook the fish. When approaching a fish, have your net deep in the water. Slowly lift the net up from under the fish and carefully put them in the bucket. Don't handle the fish as this may cause damage to the fish's slime coating resulting in the fish becoming infected with bacteria. The slime (mucus) is an important part of the fish's natural immune system.

Don't catch too many as this will overload the bucket resulting in loss of oxygen, and dead fish.

They should be released in you dam as soon as possible. Rainbows will quickly establish a self maintaining, stable population in your dam from just a few fish. 20 fish will quickly fill a farm dam, and for a garden pond even less fish are needed to establish a stable population.

It is illegal to sell any of your wild caught rainbows. Even the off-spring can't be sold without the appropriate permit from your local authority. You should also check how many you are permitted to collect.

In most Australian states it is illegal to stock the wrong fish.

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The PERCH MAN ABN 42 065 149 145

Purging your fish. Your fish need to be "finished" before delivering to the end user.

Purging or "finishing"

Some people can detect a taste that they describe as “off flavour”. Freshwater fish are often referred to as having a weedy, muddy or off-flavour. There are 3 chemicals responsible for these tastes. The weedy taste is usually caused by the algae present in ponds where the fish were raised, as is the muddy flavour caused by turbid water in pond raised fish. None of these are harlmfull, just not pleasent to the tast. Obviously this is very undesirable. The chemicals that cause these off flavours are concentrated in the skin and fat of the fish.

The remedy is simple. If the fish are held in very clean water for a few days these flavours can be removed. Generally the purging, or finishing time is 7 days, sometimes longer. It is recommended that before fish are sent to market that the grower taste test 2 or 3 fish from each batch. If there are no “off flavours” present, the product can be said to be “finished,” or market ready. When properly purged of these off flavours, these fish have excellent table qualities. The flesh is white, slightly flaky, and has a delicate, melt in the mouth texture. A tip when cooking, is to cook a little longer that you might many "sea" or salt water fish. The longer you cook them the firmer and drier the flesh will become. As a freshwater fish, the fillet is a lot more moist than salt water fish. If not cooked for long enough, the fillet can be a little "mushy" in texture. Too soft, and too moist. Another tip... The chemicals that cause these off flavours are concentrated in the skin and fat of the fish. A skin off fillet will always taste the best.

Some people believe the purging of the fish in salted water makes the flesh taste better. This is not scientificly supported. There is no actual change in the texture, or flavour of the fish due to the salt content of the purging water.

More about "osmoregulation." If you want all the complicated science click here

Although the salt in the purging water is of great benifit to the fish, (I have always said salt is the asprin of aquaculture, and should always be used when handling fresh water fish. In fact if a professional grower, or hatchery operater did not use salt, he makes things difficult for himself, and his fish.) it actually has no biological effect on the flesh. The salt content of the fishes body, including the mussel tissue will always be the same through the fishes ability to *osmoregulate the salt in its body. There are exceptions such as barramundi, but jade and silver perch undergo NO changes when kept in high levels of salt. Too little, or too much salt will stress the fish. When handeling live fish, such as harvesting, the fish become stressed, and lose salt to their "freshwater" environment. A little salt added to their water is extreamly helpful. I recomend 2 to 5 parts per thousand, (ppt). That's 2 to 5 grams per liter. A salt content of 10ppt will result in stock losses for jade and silver perch. At levels above 10ppm the fish experience difficulties balancing the salt levels in their bodies. No matter how much salt you add to the water, the fish will try to regulate the salt content of their bodies. This is known as osmoregulation. Osmoregulation is the regulation of a cells fluids. It keeps the mussel tissue of the fish from becoming to dry or becoming to fluid. It regulates the salt content and what waste to get rid of and what to keep) The salt in the purging water does help the fish to purge their gut, and helps with parasite management. It is also a mild antiseptic. It also acts as a mild anaethetic keeping the fish calmer. For greater detail on the use of salt and other chemicals to manage and treat disease go to the members area.

The PERCH MAN ABN 42 065 149 145

My contact details are all here

PERCH MAN PREMIUM CLIENT VIDEOS

These videos include -

• How to spawn jade perch and silver perch in full detail
• How to take an egg (oocytes) sample
• How to inject ovulating hormone
• Which hormone to use
• How to release larvae into a plankton pond
• How long from injection to release in plankton pond
• Management of plankton ponds
• Export packing of bulk fry
• General Hatchery design
• Farm design
• Harvesting of fry and adult fish
• Holding practices for fry prior to shipping
• How to set up a plankton pond
• How to raise perch larvae
• How to move larvae to pond
• When do you put the larvae into the plankton pond 
• How to condition breeders for spawning
• How to microchip your breeders
• How to design a plankton pond
• How to wean your fry
• How to manage/prevent diseases. No antibiotic !

They call me the Perch Man, because of my intimate knowledge of Australian perch.

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The PERCH MAN ABN 42 065 149 145

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TERMS AND CONDITIONS 

By viewing this website, or any links from this website, or engaging or paying for consulting services, you accept these terms and conditions.The information provided by  Bruce Sambell, (The Perch Man.) or any of his associates colleagues or employees, or pages and sub-directories of this website, including videos, are provided as a general service. The information and advice provided is made available in good faith and is derived from sources believed to be reliable and accurate at the time. However, the information is provided solely on the basis that persons will be responsible for making their own assessment on any matters contained or discussed herein and are advised to verify all relevant representations, statements, information and advice. Changes in circumstances after material is placed on this website or any links, or videos, may impact on the accuracy of the information. No assurance is given as to the accuracy of any representation, statement, information or advice. Neither Bruce Sambell, nor any of his associates, colleagues or employees accept any responsibility for any losses whatsoever or agents, nor any employee shall be responsible or liable for any loss, damage or injury (including death) howsoever caused (whether caused by any negligent or other unlawful act or omission of, or by associates colleagues or employees of Bruce Sambell. No responsibility is accepted, for any losses whatsoever, arising from the use of or reliance on any information, data or advice (including incomplete, out-of-date, wrong, inaccurate or misleading information, data or advice): expressed or implied information provided within this website, verbally, or in any links to videos or other websites, or expressed or implied in, or coming from, any person whosoever associated with Bruce Sambell, or Bruce Sambell himself. Any information provided here should be considered as one of many information resources available. All persons including corporate entities should consider all available information.You are solely responsible to confirm any information provided by Bruce Sambell, his associates colleagues or employees, and to consider all other sources of information available. COPYRIGHT. All material contained in this website is subject to copyright.

LIVESTOCK

By engaging or paying for consulting services, you accept these terms and conditions.Any fish handled or dealt with in any way, by Bruce Sambell, (The Perch Man) or any of his associates, colleagues or employees are entirely at the client's risk. Bruce Sambell, or any of his associates, colleagues or employees shall not be responsible or liable for any fish losses whatsoever or agents, nor any employee shall be responsible or liable for any loss, damage or injury to any fish. All persons including corporate entities should consider all available information.You are solely responsible to confirm any information provided by Bruce Sambell, (The Perch Man) his associates colleagues or employees, and to consider all other sources of information available. Any information provided should be considered as one of many information resources available.

CONSULTING

By engaging or paying for consulting services, you accept these terms and conditions.Any fish handled or dealt with in any way, by Bruce Sambell, (The Perch Man) or any of his associates, colleagues or employees are entirely at the client's risk. Bruce Sambell, or any of his associates, colleagues or employees shall not be responsible or liable for any fish losses whatsoever or agents, nor any employee shall be responsible or liable for any loss, damage or injury to any fish. All persons including corporate entities should consider all available information.You are solely responsible to confirm any information provided by Bruce Sambell, (The Perch Man) his associates colleagues or employees, and to consider all other sources of information available. Any information provided should be considered as one of many information resources available.

BUYING FISH

The Perch Man does not guarantee live arrival, unless we deliver ourselves, by bulk road tanker. The owners and staff of The Perch Man are not liable for any financial losses, in any form, or any losses as a result of fish mortalities during transit, no matter what the cause. Insurance of fish in transit is the sole responsibility of the customer. Packing densities are designed to give you the best value for your freight dollar. This will often mean a build up of ammonia and especially CO2. CO2 is the biggest killer of fish during the unpacking process! If you are having trouble with losses when you unpack please contact us for advice. If a fish is alive, in the bag, when it arrives it should stay alive when unpacked, and handled correctly.

The owners and staff of The Perch Man will not be held responsible in any way whatsoever, should The Perch Man fail to supply your order of fingerlings/fry, in part, or in total. All bulk orders are counted by weight. The quantity of fish packed in each bag is an average quantity based on the average weight of sample count done under the Aquaculture Association of Queensland accepted industry standard at the time of shipment. (See Commercial Hatchery Code of Best Practice) No claim will be considered.

Bulk orders will be confirmed once a deposit has been received. This deposit is not refundable should the order be reduced in quantity, or canceled by the customer.

Should the customer be unable to take delivery of their order, in part or in full, any postponed portion of the order shall be subject to prices current for the season delivery is made. Any agreed price is forfeited.

In the event The Perch Man is unable to supply the total number of fish during the current spawning season, any payments made by the customer will be carried over to the next spawning season when the balance of the order will be shipped. It is at the sole discretion of The Perch Man to hold the agreed price, or apply the new season price for fish delivered in the next season. The deposit will be credited against the final shipment of the total order.

Should the customer be unable to take delivery of any part of the order, this includes lack of correct documentation, the deposit is not refundable. The deposit will be held as a credit in the customer's account for a maximum of two years. If the customer does not accept delivery of the order within two years, the deposit is forfeited.

All shipments must be paid in full at least seven days before the anticipated shipping date.

In the event the shipment is canceled by the customer, for any reason, any payments are not refundable. Any costs associated with the cancellation will be deducted from the payment and the balance will be held as a credit in the customers account.

All transactions are in Australian dollars. No compensation is considered as a result of any changes in currency value, regardless of circumstances.

The consignment of the goods to the customer constitutes acceptance by The Perch Man's, of the customers offer to purchase from The Perch Man, and the customers agreement to these terms and conditions. This acceptance constitutes a contract with The PerchMan. All such contracts are formed in Childers Queensland Australia. The offerer waives his/her/its rights to be notified of acceptance of the contract.

By placing an order you agree to accept these conditions

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The PERCH MAN ABN 42 065 149 145

PRODUCTION PONDS -

PLANKTON POND MANAGEMENT and design

Why use a plankton pond? Why not just raise the larvae in the hatchery?

The proper preparation and construction of ponds and their associated structures are essential for successful fish farming. Good ponds should be inexpensive to construct, easy to maintain and efficient in allowing good water and fish management, and efficient harvesting of fish. Freshwater fishponds differ according to their source of water, the way in which water can be drained from the pond, the material and method used for construction and the intended use for fish farming. Their characteristics are usually defined by the features of the landscape in which they are built. One essential characteristic is the batter or slope of the pond banks, and the “top” of the pond bank. The top needs to be large enough to safely drive around the pond, and the slope of the pond needs to be a good angle to walk down, (Sometimes refered to as teh pond batter.) and to reduce erosion. It also provides a range of habitats that help with plankton production. Ponds must also be designed to eliminate the overland flow of water from entering the production pond. Ponds used to produce fingerlings and table fish are easier to manage, and operate if they are rectangular in shape, rather than square. Among other reasons, this makes them easier to net harvest.

See this YouTube videoRun time 22 minutes, so make a coffee. A video showing pond design in greater detail is available to subscribers of my * “Premium Client Videos.” See this introduction to Premium Client Videos. 

The drying of the pond bottom is the most practical, inexpensive and effective method of eliminating undesirable species in the pond prior to each culture period. Drying oxidizes harmful chemical substances especially sulphides, and facilitates mineralization of organic matter. It also reduces, (almost eliminates) harmful pathogens that can seriously damage the next crop of fish. In my opinion the drying of plankton ponds is essential for good plankton production, AND “my opinion,” is supported by the scientific research done for perch ponds in Australia. In order to dry and maintain a dry pond there must be a drain in the pond bottom to allow water to escape after rain events. This drain can/should incorporate a harvest sump. 

Liming fish ponds

In some circumstances it may be essential to lime ponds. 

This picture shows a harvest sump being used. Click the picture for the complete process. Run time 22 minutes, so make a coffee, it's the same as the video above. How the sump works 18 minutes, members access only.

Click the picture to see the whole process.

Fertilisation and Plankton Management of Perch Larval Rearing Ponds

Introduction

The culture of fish larvae requires specific management of ponds to enhance phytoplankton and hence zooplankton production. Fish larvae feed on zooplankton through to the transition to fingerlings. The dynamic characteristics of zooplankton populations have led researchers and commercial hatcheries to use a range of fertilisation regimes. The aims of the management techniques are to maintain high densities of desirable zooplankton species until the fish are harvested or weaned onto commercial feeds.

Types of Fertiliser

Fertilisers are classified as organic or inorganic (chemical). Inorganic fertilizers are man-made and are readily available eg. superphosphate, urea, potash etc. Organic fertilisers are manures, plant meals and other natural products eg. lucerne hay, grasses, poultry manure and cottonseed meal. The latter provide relatively lower levels of nutrients (Table 1) compared to inorganic fertilizers (Table 2) but they serve as a substrate for the growth of bacteria, protozoans and zooplankton. After more than 35 years of experience, I prefer inorganic fertalisers because the use of organic fertalisers tends to make the management of oxygen levels more difficult. The decomposition of organic fertilizers (manures etc.) involves bacteria that need oxygen. Sometimes the the bacteria population is so high and unpredictable that oxygen levels drop too low. I find it easier to avoid this issue when inorganic fertilization regimes for each pond have been developed. By this I mean, over a period of time, keep good records that show how much fertilizer is used, when it was used, (days after filling pond,) weather conditions (temperature, cloud cover, rain, etc) and plankton types and numbers. I have used DAP and urea for hundreds of plankton ponds over years of fingerling production. DAP (Diammonium Phosphate) is a widely used fertilizer in Australia, providing both nitrogen and phosphorus, which are essential for plant growth, particularly during early stages. Urea will provide the most nitrogen at the lowest cost.

Nitrogen, phosphorous and potassium (K) are the primary nutrients in inorganic fertilisers. The grade of inorganic fertiliser refers to the percentages by weight of nitrogen (as N), phosphorous (as P2O5) and potassium (as K2o also called potash). For example a 20-20-5 grade of fertiliser contains 20% N, 20% P and 5% K. Impurities and inert materials are also added to bulk out of the final weight.

Controlling Algae Productivity

Different algal (phytoplankton) species have widely varying abilities and demands for nutrient uptake and light utilisation. The purpose of fertilisation is to promote an algal "bloom" without necessarily trying to promote a particular alga species. Algae will continue to grow rapidly if the following requirements are met:

• Primary nutrients (an inorganic carbon source eg. carbon dioxide, bicarbonate; Nitrogen and Phosphorous), hydrogen and oxygen; K is not as important as P and N;
• Minor and micronutrients;
• Sufficient light energy; and
• Suitable water temperatures for growth.

From a pond management perspective, however, only N, P, K and carbon (C) are controllable. The supply of essential micronutrients has never been shown to limit algal growth in fertilised ponds and oxygen and hydrogen are supplied via the water.

Selecting a Fertilisation Regime

Most often a regime selected prior to filling the larval pond is based on previous fertilisation research and subsequent zooplankton monitoring and larval survival. However due to the many ecological differences between ponds (eg. climate, soil type, aspect) fixed-rate recipes are often not applicable from one region to another, or even between ponds on the same farm. A degree of trial and error is required when first applying a fertilisation recipe.

Algae require a supply of inorganic nutrients. Phosphorous is the single most essential element. It is relatively scarce in the aquatic environment and can be quickly absorbed into the pond bottom. Some nitrogen may be needed as well, especially in new ponds and in combination with organic fertilisers to hasten decomposition. Potassium is rarely required.

Alkalinity is another requirement to assist in promoting plankton growth. Alkalinity stabilises pH and facilitates the uptake of inorganic carbon by algae. Waters having less than 20 mg/l total alkalinity will need liming. Carbon can also be supplied to the algae when carbon dioxide is released following the decomposition of organic fertilisers. 

Applying Fertilisers

It is important the fertilisers do not come into contact with the pond bottom because the nutrients (especially phosphorous) can become bound up in the mud. Placing the fertiliser on a submerged platform allows the nutrients to go into solution in the top waters where photosynthetic activity is greatest. Suspending the fertilisers in porous bags is another option. Alternatively fertilisers can also be dissolved on the pond bank and the liquid broadcast around the pond.

When not to Fertilise

• If the total alkalinity is below 20 mg/l (phosphorous solubility will be reduced).
• If rooted aquatic vegetation or filamentous algae are present.
• If the soils are acidic or very fertile.
• If the pond is receiving a flow through of water.
• If the secchi disk reading is less than 30 cm.
• If early morning dissolved oxygen is below 3 mg/l.
• If the afternoon pH exceeds 9.5.
• If the water has clay turbidity.

Failure of Fertilisation Programs

• Inadequate quantity of fertiliser or specific nutrients.
• Acidic water or low alkalinity.
• Very hard water and pH above 8 which causes phosphates to precipitate out.
• Waters with very high clay turbidity.
• Excessive weed or filamentous algae growth.
• Low light intensity.
• Low water temperatures.

Timing of Stocking Larvae after Fertilisation

When are the larvae ready to be released. When they are all swimming horizontally and have coloured up, they are grey, (They go from transparent to grey.) and they are attracted to light. 

See this video When are larvae ready to go into plankton pond. 

The larvae in this video are NOT ready to go to the plankton pond.

The larvae in this video are ready to go to the plankton pond.

Click for video releasing larvae

How to collect the larvea from the spawning tank. I prefer to scoop the larvae from the spawning tank with their water, Place them into a plastic bag, then use pure oxygen to inflate the bag and move them to the plankton pond. This video shows the spawning tank set-up, how it drains to concentrate the larvea, tilt the tank and scoop the larvae. Some hatcheries syphen the larvae, but the way I do it is the least stressful on the larvae.

Mis-timing the stocking of larvae can result in poor survival and/or reduced growth. Ideally, the larvae should be stocked when the pond has an established bloom of algae and suitable sized zooplankton. Stocking larvae too early runs the risk of the pond having poorly established zooplankton populations. Conversely, stocking into ponds that have been filled for 3-4 weeks could cause high larval mortality due to the lack of small zooplankton and the presence of aquatic insects that prey on the larvae.

When ponds are filled and fertilised, the plant and animal populations go through predictable changes in both predominant types and sizes, a process called ecological succession. Understanding succession will greatly contribute toward success in larval culture. This can be achieved with regular plankton sampling using a plankton net and observing the plankton under a microscope.

Stocking perch larvae when rotifer populations begin to rapidly grow (7 to 10 days after filling) generally results in a successful rearing program. By the time the populations of rotifers decline the larvae have grown large enough to consume larger zooplankton. Table 3 outlines the major zooplankton groups and their approximate sizes and life spans.

IMPORTANT NOTE. My experience with the timing has been a little different to the research that has been published. I found the plankton was at its best 5 to 8 days from the start of filling, with time to completly full no more than 48 hours.

Maintaining Zooplankton and Larval Weaning

The aims of pond management are to co-ordinate the release of first feeding larvae with high concentrations of food organisms, and then maintain high zooplankton concentrations for as long as possible. The continuous application of a suitable fertilisation regime is paramount to this goal. Major influences that affect the longevity of zooplankton blooms are:

• Die-off of the algae bloom (cold, overcast weather or poor fertilisation regime).
• Overgrazing of the algae by the zooplankton.
• Predation of the zooplankton by the larvae and fry.

These factors may influence the decision when to commence weaning the larvae (fry) onto formulated feed. Under normal circumstances weaning of  perch fry can commence 2-4 weeks following stocking using a "dust" feed of approximately 0.6-mm in size. During weaning, fry should be fed 3 or 4 times per day broadcasting the feed around the perimeter of the pond. Source NSW aquaculture publications.

* PERCH MAN PREMIUM CLIENT VIDEOS

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They call me the Perch Man, because of my intimate knowledge of Australian perch. My experience has been gained over the years while the commercial development of Australian native freshwater fish grew and evolved. I was the first to breed many species, including sleepy cod and a number of Australian native freshwater fish. I was on the first expedition to collect the original breeders of jade perch from the Barcoo River, central Australia. I was one of the very first to ever spawn jade perch I am told I was the second person to breed them. This was over 28 years ago. I have now been breeding them continuously, longer than anyone currently in the industry, or anywhere in the world. In fact, the decision to use jade perch as their marketing name was made at my kitchen table.

Premium Client Videos include -

• Personalised instructional videos for staff and management

• Export packing of bulk fry

• General Hatchery design

• Farm design

• Hatchery procedures

• Management of plankton ponds

• Harvesting of fry and adult fish

• Holding practices for fry prior to shipping

The list go on . . . Everything you need to know about Australian perch aquaculture. How to condition breeders for spawning How to microchip your breeders. How to take an egg (oocytes) sample. How to inject ovulating hormone. Which hormone to use. How to release larvae into a plankton pond. How long from injection to release in plankton pond. How to fertilise a plankton pond. How to design a plankton pond. How to breed jade perch. How to breed silver perch. How to breed sleepy cod (soon hock). How to wean your fry. How to manage/prevent diseases. No antibiotic! How to design your hatchery. Farm design . . . and many more.

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The PERCH MAN ABN 42 065 149 145

SILVER PERCH - KANGAROO SYNDROME ?

Why I call it "Kangaroo Syndrome," I refer to the lack of growth when fish are overstocked. When kangaroos overpopulate an area, or there is not enough feed available they will not become pregnant. Kangaroos that live in the arid parts of Australia, in the inland woodlands and deserts, like most other marsupials are well adapted to their arid environment, shutting down their reproductive system when conditions are too dry to breed successfully, and rebooting it only when conditions improve.

Silver perch have a similar trait. They don't grow well in a RAS. (Recirculating Aquaculture System.) Silver perch hit a "growth barrier" at about 300 to 350 grams.

WHY ?

It is probably because they release a pheromone (A type of hormone.) into the water which switches off their growth when they are over crowded. It has been scientifically proven that this happens in a RAS. It does not seem to be an issue with flow through systems, or hybrid systems with some flow through. Generally, it does NOT happen in open earth ponds. To some degree this also happens with other fish species. Some species will actually become mature at a much smaller size, like tilapia for example. 

Silver perch grow extremely well in open earth ponds, also in cages in earth ponds. They will also do very well in large commercial concrete tanks, particularly in tropical climates. See this video at a commercial farm in Singapore where they grew to one kilo in a year. Note that this pond has floating vegetable rafts which remove a lot of nutrients from the water. 

 Click picture for video

The PERCH MAN ABN 42 065 149 145

 SELECTIVE BREEDING OF JADE PERCH AND SILVER PERCH - 

 

 

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The PERCH MAN 

 Click here for all fingerling prices

_{SILVER PERCH} - High in Omega-3

They are also good for aquaponicsin cooler climates where jade perch won't handle the winter water temperatures.

When grown in tanks, silver perch fingerlings will only grow to about 300 to 350 grams in about a year, given reasonable growing conditions.

Read more about tank growth here.

Unless it is a flow through system, then they will keep growing to reach about 500 to 800 grams in one to two years, depending on conditions In Singapore they have grown to 1 kg in 12 months. That's because Singapore has a year round tropical climate. Click to see video of them in Singapore
Silver perch have been farmed commercially for decades. They are an ideal fish for growing in ponds and raceways. They will also grow in tanks, however some tank systems do not produce perfect results. For reasons not fully understood, some tank systems seem to result in a growth barrier at about 300-350 grams. For hobby backyard aquaponicsystems this probably won't be a problem as 350 grams is still a good plate size whole fish. Back in 1916 silver perch were seen as a candidate for aquaculture. In the early 1980's commercial production was trialed by the pioneers of a now well established industry. The species is now grown commercially for decades in many countries around the world. The species is most popular in Asian countries. They have the potential to grow to about 6-8 kilos. (Depending on which scientist you speak to.)

This is an Australian native species from the Murray Darling River Basin, the blue area in the map above.
The Murray/Darling Basin is the largest river basin in Australia, covering a very large inland area of Australia with a broad climate range.
Parts of the basin are quite arid.
Temperature ranges are broad and water chemistry varies considerably.
This all adds up to a sturdy fish that is not too demanding on the grower.

Best results are achieved at optimum temperatures and water quality.
A temperature range between 23C and 28C is best, but they will tolerate as low as *2C and as high as 37C. (*Fisheries Action Program Australian Department of Environment 2002.)

Professional growers achieve 600 to 800 grams in less than 18 months.
This is in Australia, where winter pond temperatures result in much slower growth than can be expected in a tropical climate.
They grow on a range of commercial diets, with a wide range of fat and protein contents.
Silver perch are known to have very high levels of beneficial omega-3.
Research has shown they have one of the highest levels of omega-3 in seafood tested by the CSIRO.
It is noteworthy that the omega-3 content of the flesh will vary according to the diet used to grow the fish.
This means they not only are excellent table fish, but they are also very healthy to eat !

Silver Perch can be stocked at about 300-400 per hectare if they are not fed, and up to 1000 per hectare if you can feed them regularly. 

I recommended that, in dams, they be fed during the late afternoon. When the shadows are across the water. Feeding silver perch just before sunset will provide a spectacular display for your friends and visitors. A great talking point for a barbie.

 FOR THE FARM DAM

On the table

What do they like

Diet

I recommended that, in dams, they be fed during the late afternoon. When the shadows are across the water. Feeding silver perch just before sunset will provide a spectacular display for your friends and visitors. A great talking point for a barbie.

Silver Perch are omnivorous and will thrive in most farm dams. 

Be sure to check local regulations before stocking any fingerlings into your dam anywhere within Australia. For the Queensland information click here.

You need to do your own research for other jurisdictions.

They will eat worms and most other aquatic life including weeds.

Should you add fingerlings in the future the older fish are very unlikely to eat the new fingerlings. They readily take artificial food, such as aquaculture pellets, chook pellets or bread.

Bread or chook foods are not the best of diets for fish but will do in small quantities. Aquaculture pellets are a properly balanced diet and fish will thrive on these commercially available foods.

As the Silver Perch soon come to know when they will be fed, they will be ready and waiting near the surface at feeding time.

I recommend silver perch be fed during the late afternoon when the shadows are across the water. If they are fed early in the morning there is a risk that birds may eat your fish before you are up and about, especially in summer when it is light very early.

Remember the fish will be congregating in one spot waiting to be fed.

Feeding silver perch just before sunset will provide a spectacular display for your friends and visitors. A great talking point for a barbie.

Silver Perch that are being fed are very easy to catch, just add a hook to their food!?

Otherwise use worms fished on the bottom with a very light float.

Silver Perch are excellent eating but can sometimes have a weedy or muddy flavour.

It is best to hold live fish in very clean water for a week if the flavour is not pleasant. Alternatively, only take fish for eating from your dam during dry spells when there is no run-off into the dam, and water is clear, not muddy or green.

WHAT DO THEY LIKE

Best temperature range 23C and 28C. They will tolerate as low as 2C, and as high as 37C.

They will continue to grow well at temperatures above 15c. 

Best pH range between 6.5 and 9. 

Tolerate pH levels between 6 and 10  Salt Salinity levels of 5 grams per litre are safe.

Diet

Silver Perch are omnivorous and will thrive on most diets.

Although they might eat fish that can fit in their mouth, they are not really considered serious predators. 

They will eat worms and most other aquatic life including weeds.

Should you add fingerlings to a dam in the future the older fish are very unlikely to eat the new fingerlings.

They readily take artificial food, such as aquaculture pellets. Aquaculture pellets are properly balanced diets that the fish will thrive on.

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The PERCH MAN ABN 42 065 149 145

FISH HEALTH CERTIFICATION PROGRAM (FHCP)

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The PERCH MAN ABN 42 065 149 145

My contact details are here

It's not so easy to find jade perch, or any Australian native freshwater fish, in any retail outlet in any of the Australian cities. There is not enough production for it to be offered to the broader market. It's a long story, but essentially most of these fish come from family businesses. Farms run by families. They are all making a good, secure living. It would be a big move, and risk, to jump to the "broarder market", supermarket outlets. The Asian community in our cities pretty much consume all the production. I personally have been looking into the option to have it delivered to "mum's" door. It's an obvious market, health conscious mum, or just generally health conscious people that want to eat this regularly. The best I can do at the moment is send it in box lots, of whole, chilled jade, or silver perch, to your local airport, and you collect it there. 

The PERCH MAN ABN 42 065 149 145

All my contact details are here

The PERCH MAN ABN 42 065 149 145

In the Client area you can find information like this . . . 

Yes, I'm still active in the aquaculture industry. I sold my farm after 35 years. I am not interested in waiting around for my “heart attack” I’d rather keep active while I “wait.” (I'm in my mid seventies now.)

Now I am keen to help others develop Australian native freshwater fish farms.

I am very actively involved in consulting, which really means I am an active "teacher" of the things I learned when I developed my farm from 200 acres of bush land into the largest farm of its type in Australia. I don't really have the time available for those who are not in a position to develop into serious producers. However, for those who are serious, and actually have the potential to succeed, I am very keen to pass on skills and tricks I learned and discovered during the development of some of Australia’s freshwater fish into commercial species.

 Click for short video

I am still selling fish to anyone interested in growing them as a hobby, (Small quantities only for Australian customers.) and to those that want commercial quantities, especially export markets. I can deliver almost anywhere in the world. See this page for details

Do you know the difference between a good and a bad consultant? A bad consultant knows everything. A good consultant knows, he does not know everything, but he knows where to get accurate information for you.

Bruce Sambell, often called the Jade Perch Man, or Perch Man, is the founder and designer of Ausyfish Bruce has been involved with fish at a commercial level for over 40 years. His role as industry consultant has provided cross sector experience at many levels. Sound advice is available to existing industry participants and especially those considering entering freshwater finfish aquaculture. Bruce has gained considerable experience over the years as the commercial development of Australian native freshwater fish evolved in Australia. Bruce was the first to breed many species, including sleepy codfreshwater archer fishand a number of Australian native freshwater fish including silver perch Australian rainbow fishcoal grunterAusytalian bassand Murray cod Bruce also produced many varieties of exotic ornamental fish 

Bruce was one of the first to ever spawn jade perch He was on the very first expedition to central Australia to collect the first ever, wild jade perch breeders.He has now been breeding them continually, longer than anyone currently in the industry. 

Bruce was the founding president of the Aquaculture Association of Queensland Inc(AAQ) (For about 20 years.) Bruce was also Vice President of the Queensland Aquaculture Industries Federation Inc., (QAIF) for over 3 years. Bruce sat on the committee of QAIF for over 14 years. Bruce also sat on a number of Government bodies as an industry consultant, including the Queensland Department of State Development and Innovation's Aquaculture Reference Group,  the Queensland Freshwater Management Advisory Committee, the Translocation Sub-Committee for freshwater fish, and Queensland's Stocked Impoundment Permit Scheme Sub-Committee. (An advisory body for stocking freshwater fish in lakes and rivers throughout Queensland for recreational anglers.) He was also the industry "food safety" representative for a number of years. As part of his role as industry leader he coordinated many major aquaculture conferences and training workshops. He also sat on several regional advisory bodies, including, the Fisheries Regional Development Committee for Hervey Bay and the Fisheries Regional Development Committee, Bundaberg.                                                                                                                                                                                            

Why is this webstite here ?

A long time ago my best friend and mentor said that I should write a book.  (Thanks John.) 

To access this area of the jadeperch web site click on "membership" on the top menu bar. Once you have signed up you will notice that the "membership" button on the menue bar now has a "Technical Information" drop down list. Just click on Technical Information, and you are in.

My contact information is here 

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The PERCH MAN ABN 42 065 149 145

Want fish that are table size 

Click to contact me

It's no so easy to find jade perch in any retail outlet in any of the Australian cities. There is not enough production for it to be offered to the broader market. It's a long story, but essentially all these fish come from family businesses. Farms run by families. They are all making a good, secure living. It would be a big move, and risk, to jump to the "broarder market", supermarket outlets. The Asian community in our cities pretty much consume all the production. I personally have been looking into the option to have it delivered to "mum's" door. It's an obvious market, health conscious mum, or just generally health conscious people that want to eat this regularly. The best I can do at the moment is send it in a box lots, of whole, chilled jade, or silver perch, which you must collect from your local airport, and you collect it there. 

 

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The PERCH MAN ABN 42 065 149 145

Australian Honey Herch (Hephaestus fuliginosus)

Honey Perch are a popular sport fishing species found across the tropical regions of Australia. 

Click for video

Abundant throughout coastal drainages of Northern Territory, Gulf of Carpentaria and North Eastern Queensland. Sports fisherman know them as sooty grunter. They are also known as black bream in some areas, however, there are many freshwater fish in Australia that local citizens call black bream. They have a white flaky flesh, with a delicate flavour considered by many people in Australia to be superior to other freshwater fish. The species will be new to aquaculture. Currently they are being trialed in Singapore, Malaysia and in Hong Kong the Inland Culture Development Section of the Agriculture, Fisheries and Conservation Department are conducting research on the species.

They readily accept commercial pellets. Even wild caught fish kept in tanks readily accept any food. Water temperatures should be in the range of 25 to 30c. They grow to about 54 centimeters and can weigh over 6kg. They can manage PH as low as 4.0 and temperature ranges between 11c and 35c. For best growth, maintain them between 25c and 30c. They are an Omnivorous species. Diets that are suitable for jade perch, silver perch or tilapia would suit honey perch. Although, they are generally not aggressive towards each other, because this species has not yet been grown in intensive aquaculture systems, careful observation should be practiced to monitor any potential cannibalism or agressive behavour. As I always say, if it is small enough to fit in their mouth, it will probably end up in there !

We choose our breeders for their shape, and most important, their colour. We also use fish that are from east of the Great Dividing Range, and from the western side. The genetic difference may result in faster growth rates. Although, technically they are the same species, there is a very great historic distance between the two populations. This may well result in some (hybrid) growth vigor.

Very similar to khaki grunter but haslonger head profile. This can be seen in the picture below showing both species. When pelvic fins pressed against the body they don´t reach the anus as it does with the khaki grunter. 

Fry prices.

30 - 49       ---      $2.31 each  Inc GST

50  - 99    ---      $1.87 each  Inc GST

100 - 499  ---     $1.65 each  Inc GST

500 - 5000  ---   $1.43 including GST

First ever fry were shipped in February 2020. Order now for the 2020-21 season. Minimum order 10,000 fry at AUD$0.55 plus shipping costs. Limited numbers available. Orders will be supplied on a first ordered, first supplied basis. See video of fry here.

Shown below left is a honey perch with a Khaki perch. These fish were just caught in the wild and photographed immediately. To see full size pictures, right click and open in new tab. Below right are honey perch fry.

Below: Honey Perch and habitat To see full size pictures, right click and open in new tab.

Habitat

The PERCH MAN ABN 42 065 149 145 

Sleepy cod or soon hock or Australian marble goby

More information can be found in the Members Area

Right click most pictures on this website and open in new tab to see full size image

Click pictures below for video

NOTE: To view full size image, right click and open in new tab.

Below a male Australian sleepy cod breeder.

Below a very rare gold form of Australian sleepy cod.

One of the most promising fish for future aquaculture. 

• This fish has many qualities that give it all-round appeal as an aquaculture species
• It has been argued that this species has the best eating quality of all Australian freshwater fish
• Extremely easy to transport at high densities
• High flesh recovery
• Can be kept and grown in high densities
• Perfect in a RAS
• The Fitzroy/Dawson River strain grows better than northern strain for aquaculture
• Recirculating systems necessary for grow-out
• Must be stocked at high densities
• High fat diets, (15-20%) are undesirable as the fat damages the liver, this will affect FCR because the liver is an important part of the digestive system
• Placid and easy to handle
• No spines in fins or gills
• Fitzroy/Dawson strain genetically distinct from northern strain
• Sleepy cod grow faster in tanks than in ponds
• Males grow slower
• Best above 26C. Below 22C not recommended, with problems below 18C
• They can produce huge numbers of eggs, up to at least 170,000 for larger fish! Information on breeding is available to clients. click here

COLOUR

The pictures below are of the Kimberley fish. This is a very rare catch made on 2020 by researchers. It was returned to the water unharmed.

Below, click for video. Left, large sleepy cod, right fingerling video.

Here is a link to the playlist about sleepy cod on my YouTube channel

HOW MANY SLEEPY COD SPECIES ARE THERE ?

• Oxyeleotris lineolata (Sleepy Cod): Found in Australia, this species is characterized by its dark brown color with paler sides and indistinct darker stripes.
• Oxyeleotris marmorata (Marbled Goby): Known for its marbled or mottled appearance, this species is found in Southeast Asia.
• Oxyeleotris selheimi (Blackbanded Gudgeon): Also found in Australia, this species has a dark brown coloration with narrow dark stripes along the sides and small dark spots on the fins.
• Oxyeleotris fimbriata (Fimbriate Gudgeon): This species is found in New Guinea and is characterized by its distinct markings and coloration, with a pale brown head and back, dark brown sides, and a whitish belly.
• Oxyeleotris aruensis (Aru Gudgeon): Found in New Guinea and surrounding islands.
• Oxyeleotris heterodon (Sentani Gudgeon): Found in Lake Sentani, New Guinea.
• Oxyeleotris nullipora (Poreless Gudgeon): Found in Australia.
• Oxyeleotris stagnicola (Swamp Gudgeon): Found in New Guinea.
• Oxyeleotris urophthalmoides: Found in Southeast Asia.
• Oxyeleotris urophthalmus: Found in Southeast Asia.
• Oxyeleotris wisselensis (Paniai Gudgeon): Found in New Guinea.
• Oxyeleotris altipinna: Found in New Guinea.
• Oxyeleotris caeca: Found in New Guinea.
• Oxyeleotris colasi: Found in New Guinea.
• Oxyeleotris herwerdenii (Blackbanded Gauvina): Found in New Guinea.
• Oxyeleotris paucipora: Found in Australia.
• Oxyeleotris siamensis: Found in Southeast Asia.

My contact details are all here

(Reference)

Welcome to the Perch Man website. 

The PERCH MAN  Site last updated January 15th 2026

Jade perch and silver perch fingerlings available now.

See link to prices below.

This website containes knowledge gained over almost 40 years.

You can find information about many Australian native freshwater fish species.

You can order fingerlings here too.

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MORE INFORMATION LINKS

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WARNING imposter fish details here

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HOW TO USE THE MEMBERS AREA

To sign up, and pay the membership fee, email me directly. This email address is being protected from spambots. You need JavaScript enabled to view it.

To access this area of the website click on "membership" on the top menu bar.

Once you have signed up you will notice that the "membership" button on the menue bar now has a "Technical Information" drop down.

Just click on Technical Information, and you are in. 

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The members area has detailed information about Australian freshwater fish, including growing and disease management  

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All my contact information is here

The PERCH MAN ABN 42 065 149 145

Click to find out if these fish are suitable for farm dams

See to bass being spawned   Click to see half a million tiny baby bass

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The PERCH MAN ABN 42 065 149 145

For positive results based on "The Perch Man's" method see the members area of this website.

The following information is the results of research by Brett Herbert, research scientist for the Queensland Fisheries Department. The work was done at Freshwater Fisheries and Aquaculture Centre Walkamin Far North Queensland, Australia. It should be noted that the variety of golden perch used for the weaning trials were not from the Lake EyreSystem. 

The following details the method we have used to wean golden perch fingerlings.  You may find it of use if you are to wean fish this year.  Our survival rates in mass rearing have been good, with up to 98% survival. Fingerlings 20-25mm total length do well, using a 1mm skretting salmon crumble starter diet. The Ridley’s starter diet is too big. If you get bigger fish a bigger crumble could be used, but 1mm will get you through.  It is best to have all the blocks made up beforehand. We work on about 50-60mL plankton slurry  per 1000 fish.

Our most successful method to date is as follows:

1. On receipt of fingerlings feed frozen plankton, until fish are through transport shock, quarantine, and prophylactic treatments are completed.  This may take up to a week (usually a couple of days).  Advised treatment is 70ppm formalin with 10‰ salt for one hour.  The fish must be watched carefully for the duration of the treatment and strong aeration maintained.
2. Start feeding frozen blocks of plankton slurry.  We habituate the fish to being fed in a specific place in the tank at specific times.  We feed three times a day.  Water and aeration are turned off so there is no current in the tank. Frozen blocks are placed in a plastic mesh basket (gutter guard or similar), hung on the side of the tank at the water surface. Plastic mesh is about 10mm2.  The cover of the tank is pushed back a little on each feeding occasion as the fish don’t like bright light.  The amount of food required is determined by observing the amount of plankton left circulating in the water thirty minutes or so after feeding. It is important to know how much they eat so as not to feed to excess during weaning.
3. Fish were observed feeding.  Once the majority of fish were rising to the blocks and actively feeding, the weaning process began.
4. Frozen blocks of plankton/crumble mix (we use 1mm skretting salmon starter crumble) replace the plankton blocks.  The ratio of plankton: crumble  is reduced by 10% each day.  We use volume to measure, starting with 10% crumble to 90% plankton, reducing plankton and increasing crumble by 10% each day. Use a slurry of plankton. The higher proportions of crumble mix will be dryish, do not add water when mixing as if you do it stays in a lump and does not fall though the mesh.  It also fouls the water very quickly if too wet.    Over mixing makes it go to a gooey paste which does not work. It is best to mix the fresh, chilled plankton with the crumble. Do not freeze the plankton and thaw it for mixing. If the mix is dry and unlikely to hold together (usually only the 80% and 90% crumble mixes are like this) you can add water after the mix is partly frozen, and then freeze it completely. That way you are not mixing water and crumble excessively, and it will behave well.
5. Weaning takes 9 days.  The crumbles are then fed by sprinkling on the surface in the same place as the basket was.  Observe the fish-they should still be coming in to this area to feed.  We continue feeding crumble alone for two weeks during which most non-feeders will die off.

Notes:

Artemia could be substituted for plankton if desired.  However, Artemia fouled the water more quickly than plankton.

Cleaning on a daily basis by scrubbing the tanks is essential.  Flushing just after feeding is essential due to the fouling effect of the moistened frozen crumbles. Plankton-crumble mixes of 50-80% crumble foul the water worst.

The plankton size should be <1mm and >200mm (for 25-35mm fingerlings).  Our plankton of this size was primarily Moina, juvenile Daphnia, and copepods. We make the mixes up each morning with the fresh plankton. We chill it first so it is cold and use crumble stored in the freezer. The final mixes (80 and 90% crumble) will probably not hold together, add water in the mould when freezing. Put the mesh bag in and then sprinkle the crumbly mix above the bag.  Only mix until the plankton and fish food are well combined-too much mixing and the fish food goes like mud. It will not break up and fall through the basket.

The plankton slurry is a consistency that will hold its shape for a short while-if you take out a spoonful and place it on top of the slurry it will gradually sink in. If it disappears straight away it is too thin. Likewise, if a spoon stands up in the slurry it is too thick. 

Introduction of fish into ponds where any other food source is available may result in the fish going back to alternative food.  We have fish in cages in ponds feeding on artificial food.  

All attempts at weaning fish “cold turkey”, with or without presence of weaned ‘trainer fish’ were unsuccessful.  We had a maximum survival rate of 20%.  We did find that these fish grew as fast as the best of the weaned fish.  This suggests that possibly some fish are predisposed to eating whatever is available, and these are the fastest growing.

If you have any questions, or would like to clarify any points on the above, do not hesitate to contact us. (Contact details at the bottom of this page)

Growth of Fingerlings.

From a start weight after weaning of about 1g, fish grow to an average of about 12-14g after three months. In our ponds, 28-64% of fish were less than 10g at three months.  I suggest grading at this point. I will not predict what level you might have, with any luck it will be at the lower end.

With a starting average weight of  about 15-20g after grading, another grade could be done after about 4 more months. By this time there should be a clear distinction between the non-performers and the racers. Our results had about 20% of these fish not performing (i.e. only 20-40g four months after grading).

Food For The Fish.

We have only found one supplier who reliably supplies a sinking pellet. Skretting has sinking barramundi and salmon diets. There is no difference in the crumbles.

Primo is importing a fish food, which has a low fat content and may be better for the fish.  We have tried it and found that it floated.

Golden perch feed on the bottom for several hours after feeding.  If possible, adjust circulation to retain pellets in raceway for as long as possible. In your water their feeding behaviour might be different.

Pellet size is dependent on the size of the fish. You may find that you need to use different sizes of pellet to those recommended here.  Do not change over pellet sizes abruptly, as some fish choke to death on the larger pellets if you do. By monitoring left over feed you will see if certain size pellets are no longer being eaten.

Amount of Food.

 We have found this relies on the quality of the food, but is quite variable.  Food consumption will have to be monitored carefully and adjusted regularly.

In our experience, golden perch food consumption does not drop as temperatures drop. (Your temperatures being considerably lower may reduce food consumption).

 *This is in ponds. Monitor feeding closely. We found that the midday feed stopped increasing after about two months and then fish stopped eating at midday.  Likewise, after about 4 months the morning feed was less used and could be dropped. 

 Note: These average sizes are based on our removal of 50% of smaller fish in our ponds. As we had up to 64% of fish in the small size classes, some of our ‘large fish’ ponds have a substantial number of smaller fish in them, which pulls down the average.

To order fingerlings email This email address is being protected from spambots. You need JavaScript enabled to view it.

Golden perch are ONLY found in Australia

There are three species of Golden Perch.Macquaria ambigua ambigua, Macquaria ambigua oriens, Macquaria Sp.

The species from the Murray Darling River Basin is Macquaria ambigua ambigua.

The first commercial supplies of golden perch fingerlings were supplied to grow-out farms in Australia were from the Lake Eyre strain.
These fish have shown excellent growth.

One grower reports that they grow much faster than silver perch.
This grower was using large round polly tanks.
In his words the fish are described as "..the barramundi of the inland.."

After 40 days the fish had grown from about 1gm to an average size of 25gm.
The fish were graded into three average sizes, 50gm, 24gm and 12gm. One fish was 112gms.
After 75 days they are estimated to be an average of 40-50 gm.
This is an estimate as the water temperature was 14-15C, and handling was considered an unnecessary risk at this relative low temperature.
This grower says they eat actively at 15C, and at 12C still feed but not so eagerly.
After  100 days the average of the larger fish was 108gms.
The largest fish was now just over 200gms.
The average of the fish in the medium size range, (which is now two thirds of the population) is 80gms.
The grower reports that they have gone from 20gms to 80gms in only two months! The FCR, (food conversion rate) over the range of sizes is between .8 and 1.7 to 1 This is using dry food.

 

• Sex ratios –males dominate (60%)
• Females split into two groups-ones that don’t grow and ones that grow.
• Body shape significantly different after 150g (♀ heavier).
• Female growth slower initially but catch up at about 6-9 months.
• Juvenile ♀ were more susceptible to handling stress.
• When an average size of 600g+ is achieved, pond is ready to harvest.
• Fish sizes will range from 350g to 1kg+ (90%>450g).
• This takes from 14-18 months.
• Grow out from 200g to market size is relatively quick.
• Temperatures >15°  100g per month is achieved, sometimes more

Conclusions
Feed a sinking pellet, 40% protein.
Monitor feeding closely-size, quality, regularity.
Maintain water quality.
Realise that only 50% of fish may grow, bank on 30%.
Sample product before harvest! (Taste)

• Click here for weaning golden perch

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The PERCH MAN ABN 42 065 149 145

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General information collected, and observations from the natural habitat of jade perch, and the Lake Eyre strain of golden perch.

 Map source

More on Golden Perch

On a trip to the Barcoo River in July 2014 the following water quality measurements were taken;   Temperature at surface 14.6C Two meters below the surface 14c.  Hardness. General hardness 51ppm carbonate hardness 40ppm. PH 7.4. Conductivity less than 200. Ammonia 0. 

On a trip to the Thompson River in August 2018 the following water quality measurements were taken; (Note, the Thompson River is very close to the Barcoo River. It is part of the same system that drains into the Lake Eyre Basin.   

Temperature Taken at 4 sites. At 1 meter below the surface 18c.  At the surface 19c. Note, it was quite windy every day. There was considerable wave action which might explain the reduced difference between 1 meter and surface temperatures.  Hardness. General hardness 50ppm. PH 7.7. Conductivity less than 200. Ammonia 0. Dissolved oxygen 9.7 Salt Measured with a refractometer, 0.

I also measured the water temperature at the Avington Waterhole on September 16, 2024. Temperature was taken 1.5 meters below the surface at 9am on a cloudy day. It was 19c. The Avington Waterhole is quite a large waterhole on the Barcoo River.

Below is where Avington Waterhole is in relation to Northern Australia. You can see is is just on the edge of the driest, arid area of Central Australia. The second picture shows the waterhole. As with most waterholes on the Barcoo River, it is relative small, and yet so many fish have become adapted to survive in such a hostile environment. The blue dot is my camp site.

Both the Barcoo, and the Thompson Rivers are a series of water holes that only experience water flows about every 4 or 5 years. Their waters are very muddy. Gennerally, if you placed your hand in the water, you cannot see the tips of your fingers because of the suspended clay in the water.

For full size images, right click, then open in new tab. Also see video links; 

Jade Perch Story part 1

Jade Perch Story part 2

Jade perch story part 3

Below: Thompson River

Below: Dawson River

Below: Barcoo River

Below: Murray river

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The PERCH MAN ABN 42 065 149 145

Quality fingerlings don't just happen.

Quality fry/fingerlings are the result of good brood fish management. We produce fish, specificly for grow out farms. For over a quarter of a century we have been line breeding our fish. Selecting for desirable qualities such as body shape, disease resistance, spots, and of course, fast growers. Our breeders have been selected each season from fish obtained from our fingerling customers in Australia and our own "super shooters", and fresh wild fish. That is many generations of line bred fish!

No hatchery anywhere has this history of line breeding Australian perch !

The fish we select from our Australian fingerling customers have been chosen from the first harvest of grow-out ponds. This means, we chose, usually about 50 fish from the very biggest of the pond being harvested, for the first time. That is, 50 out of thousands of fish. We also keep some fish from our own fingerling ponds. These particular fish are exceptional growers. I call them "super shooters." When we stock one of our ponds with larvae to grow on to fry for our customers, there are often a couple of fish that stand out. The pond harvest is tens of thousands of fish, and 2 to 5 of these fish are outstanding. The average weight of the fish being harvested may be about .3 of a gram, but these super shooters weigh many grams each. Hundreds of times bigger than the other fish in the pond.

We also, under special permit, collect fresh wild fish to prevent our fish from becoming, inbred. We do this under advice from scientists and geneticists. They are the experts, and they advise us that if we don not introduce fresh wild genes we may find issues developing in our fingerlings and fry. Issues such as physical deformities, poor disease resistance, poor growth perfomance. Poor growth performance may manifest itself in a number of ways. Slow growth over the entire grow-out phase, or poor growth performance after the fish reach a certain size. For example, fish may reach 500 grams quickly, but do not reach 800 - 850 grams as quickly as they did in earlier generations of fish. Australian growers reported, very early in the history of the perch grow-out in Australia, that it was easy to grow fish from 500 grams to 800 grams. They reported that this is where the easy profit was to be made. That is not the case now, with some farms. Those farms find that the fish growth slowed noticeable after 500 grams. This can be common in some species of fish. Take tilapia for example. This species can stunt readily. They have been commonly reported to become reproductive at a very small size, with very slow growth performance. This should be taken as a warning that inattention to genetic management can and does result in catastrophic loss of profit to grow-out farms.

Another vital consideration not to be underestimated, is the great advantage perch have to grow and survive in hostile conditions. This is particularly relevant for jade perch. Their natural environment is far from perfect. To survive and grow in the wild, these fish must possess genetic qualities that make it possible to survive and thrive in such impossible conditions. This is one of the reasons we regularly introduce "wild" genes" from wild breeders collected from the Barcoo River. This helps to maintain these desirable qualities in our fry. Disease resistance, body shape, colour, and spots are the "aquaculture" qualities we need to maintain.

Read more about our breeding program

Click to see the Barcoo River for yourself.

Click to see how we collect wild breeders

One of the important ways we manage our genetics is the use of micro chips. Breeders are micro chipped so we can identify individual fish. We know exactly which fish were the parents of every batch of fry/fingerlings.

We have enhanced our management of brood fish to avoid inbreeding. Other countries have experienced inbreeding issues which have resulted in the loss of disease resistance, and slow growth rates over 500 grams. Spots have also been lost by some hatcheries. We have been line breeding for over 25 years. Wild fish are introduced into the blood line at intervals to maintain the desirable qualities jade perch inherit from their ancestors. Scientists have advised us that we need to introduce wild genes to avoid loosing the special qualities that are so desirable in jade perch, such as fast growing, and disease resistance. Spots are something we have recently been selecting for because of requests from Asian customers.

 See this YouTube video

What is a microchip?
Microchips, or PIT tags, Passive Integrated Transponders, are used for identification of individual fish.

They are inserted under the skin or into the muscle of the fish, usually next to the dorsal fin. They are inserted using a, single use, special applicator. The micro chips do not interfere with an animal’s normal functions. This process is carried out while the fish is anesthetized. Anaesthesia is recommended for the safety of the fish as struggling during handling can result in injury to the fish and the person inserting the chip.

A microchip is a small electronic device about the thickness of a ball point pen refill, and about 12mm long.

Each microchip contains a silicon chip that is encoded with an individual number. The components are sealed in biocompatible glass which renders the chip inert when implanted into an animal. To read the number, a scanner is moved over the implanted microchip and a signal passes between the chip and the scanner. The scanner translates the signal and displays it on a screen as a number. 

Prior to implantation, the implant site is swabbed with dilute antiseptic (e.g. Betadine or alcohol). We inserted the chips on the left side at the base of the dorsal fin. Glass chips should not be used if there is any chance the fish may be used for human consumption. 
Tissue glue is used to seal the insertion site. 

References
Australian code for the care and use of animals for scientific purposes (8th Edition 2013). 

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The PERCH MAN

SILVER PERCH FINGERLINGS    

Fingerling prices are here  To order fingerlings or fish food email: This email address is being protected from spambots. You need JavaScript enabled to view it. 

My other contact details are here

 click to see 65,000 silver perch dance to music

BUY SILVER PERCH FINGERLINGS

They are also good for aquaponics in cooler climates where jade perch won't handle the winter water temperatures. When grown in tanks, silver perch fingerlings will grow to about 300 to 350 grams in about a year, given reasonable growing conditions. Unless it is a flow through system, then they will keep growing to reach about 500 to 800 grams in one and a half to two years.

ALL SILVER PERCH ARE POND WEANED TO COMMERCIAL FEED

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The PERCH MAN ABN 42 065 149 145

WHAT IS THE DIFFERENCE?  

3.     The meat quality between Jade Perch, Silver Perch and Sleepy Cod.

Silver and jade perch have different fat content. Westerners prefer the silver perch because it is less fatty. Asian taste prefer jade perch because of the flavour of the fat. In fact, one of my clients in Hong Kong told me silver perch does not have enough flavour. He prefers the blend of fat and lean meat which gives it its distinctive flavour and texture. Personally I like both, but the silver perch does have a more delicate flavour. Sleepy cod are quite different to the perch. They have very little fat in their meat. The flesh is more flaky than perch. It has been compered to high end reef fish. It is generally considered to be the best freshwater table fish in Australia.

4.     The market acceptance in Australia between Jade Perch, Silver Perch and Sleepy Cod.

All of these species have enjoyed market acceptance to the point that there is never enough production to meet demand. The supply has been almost exclusively absorbed by the Asian community in Sydney and Brisbane, with Melbourne only receiving a trickle of production. The production of these fish in Australia is from relatively small family business. These businesses have been steadily increasing production as their business model has allowed. No major cooperate investment has occurred. Supermarkets chains have not been able to find significant, reliable, long term supplies.

Hints and recipes for jade and silver perch

Want fish that are table size 

It's no so easy to find jade perch in any retail outlet in any of the Australian cities. There is not enough production for it to be offered to the broader market. It's a long story, but essentially all these fish come from family businesses. Farms run by families. They are all making a good, secure living. It would be a big move, and risk, to jump to the "broarder market", supermarket outlets. The Asian community in our cities pretty much consume all the production. I personally have been looking into the option to have it delivered to "mum's" door. It's an obvious market, health conscious mum, or just generally health conscious people that want to eat this regularly. The best I can do at the moment is send it in a box lots, of whole, chilled jade, or silver perch, which you must collect from your local airport, and you collect it there. 

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Freshwater fish have a muddy or earthy taste

Click here to find more recipies

This recipe won the Aquaculture Association of Queensland 2018 cooking competition

Prep time 20 minutes. Cook time 25 minutes

Ingredients

1 kg Sushi rice
1 bottle Sushi seasoning
4 Jade Perch fillets
2 cups mirin
Japanese rice wine condiment
2 cups light soy sauce
Preferably Japanese style
1 cup Brown Sugar

Instructions
1:cook sushi rice according to packet instructions. Then add sushi seasoning and cool on flat tray. Place weights on rice to make a firm even rectangle and chill.
2: Combine mirin, soy sauce and sugar in a pan and reduce by half.
3: Carefully fillet your Jade perch remove all pin bones and de-scale.
4:Place Jade perch fillet on grill, BBQ or in frying pan. Brush sauce over fish and continue turning and brushing sauce layering more and more sauce each time the fish is turned over.
5: Cut chilled rice into small rectangles and then add lacquered fish fillets on top of sushi rice.
6: Serve with pickled ginger, soy sauce and wasabi.

This recipe won the Aquaculture Association of Queensland 2017 cooking competition.

Prep time 30 minutes.  Cook time 15 minutes.
Ingredients

 4 Jade Perch fillets
10 fl oz Chicken Stock
1/2 cup soy sauce
1/3 cup Brown sugar
1 tea spoon grated fresh ginger
1 table spoon cornflour
1 orange juice and zest

Instructions
1.  In a saucepan whisk together stock, soy, sugar, ginger, cornflour, orange juice and zest.
2. Bring to the boil, whisk lower heat and cool.
3. Place fish fillets in glaze and refrigerate for one hour.
4. Sear fish on BBQ or grill 2 minutes each side. Lower heat and cook through for a further few minutes depending on fish thickness. Be careful as glaze burns easily.
5. Pour remaining sauce into a small saucepan and boil then pour over fish and serve.

The following recipe was prepared by Martin Nash
BELOW Martin Nash and the perch man with a pair of jade perch at the Ausyfish hatchery	BELOW Martin Nash, Ausyfish trainee graduate, helps harvest jade perch at Ausyfish hatchery

Thai Fish Cakes with cucumber sauce

Ingredients

500g silver perch or jade perch fillets, de-boned

2 teaspoons Thai red curry paste

pinch of salt

1 tablespoon fish sauce

3 snake or green beans, thinly sliced

1 tablespoon coarsely chopped coriander leaves

corn, vegetable or peanut oil

Method

Cut the fish into 2cm (3/4") cubes and blend in a food processor until it becomes a paste. Then add the fish sauce, paste and salt and blend for about 30 seconds. Transfer it to a bowl and mix the beans and coriander in thoroughly with a wooden spoon. Dip your hands in cold water first to prevent the mixture sticking, then take a small amount of mixture and make flattish fish cakes about 5cm (2") diameter and 2.5cm (1") thick. To cook, shallow fry them in a fry pan by heating the oil and frying them on both sides for about 2 minutes each, turning only once. Drain them on kitchen paper. Serve with cucumber dipping sauce.

Makes 12 fish cakes

Cucumber Sauce

Ingredients

80ml water

60ml white vinegar

60g sugar

1 teaspoon salt

1 cucumber

1 shallot or small onion, thinly sliced

1 small red chilli, seeds removed and chopped finely

1/2 tablespoon fish sauce

4 stalks fresh coriander, finely sliced

2 tablespoons very finely diced carrots

1 tablespoon chopped roasted peanuts

1 tablespoon chopped coriander leaves

Method

Over a medium heat, in a small saucepan, bring to boil the water, vinegar, sugar and salt. Remove from heat and cool. Peel and slice the cucumber in half along its length then slice thinly. Place in a bowl and add the shallot or onion, chilli, fish sauce, coriander stalks and carrots and mix. Add the cooled vinegar mix. Garnish with chopped peanuts and coriander leaves just prior to serving with the fish cakes.

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The PERCH MAN ABN 42 065 149 145

Why would you use a microscope? 

Early detection can save fish losses, which equals saving you money. A microscope will help you identify diseases. 

Click hereto see how to use your phone to record video and take pictures from your microscope. You can send me pictures so I can help you with any issues you might have,

In a basic aquatic environment, Host + Pathogen + Unsuitable Environment = Disease. Growing fish in an artificial environment usually = unsuitable environment. Its not that your have a bad system, or something is wrong with your pond or tank water. It's just that it is not a natural environment. Particularly when it comes to stocking density. Therefore if we had a situation free of any one of the above mentioned components, will reduce or remove the possibility of disease occurring.  Disease causing organisms are usually present most of the time, even in good conditions, and especially in open ponds. All it just takes a stress of some kind, whether it be temperature, water quality, handling etc to occur and this stress can reduce the fishes natural immune response.  Whilst the immune response of the fish is hampered, diseases are able to take hold, probably affecting productivity and fish performance or even to the point of killing them. Neither scenario makes for profitable farming.  That’s where microscopes can be a powerful management tool to a fish grower. You need to know how to use them and what sort to use.

There three main types of microscopes, the Stereo Monocular and Binocular and Dissecting Microscopes.

Common infections include:

• Monogenean infestations from Gyrodactylid or Dactylogrids, commonly referred to as flukes, a type of parasite.
• Ectoparasitic Protozoans such as White Spot (Ich Infection), Chilodonella & Trichodina, also types of parasites.
• Bacterial, Columnaris Infection
• Fungal Infection, Saprolegnia

 The members area of this web site has detailed information about jade perch, including growing and disease management  click for more

A medium powered Binocular microscope.	CENTRE: Dust and moisture are the enemy of microscopes. keep them covered or in their box when not in use.	A high power binocular with camera.
	LEFT: This low power dissecting microscope is ideal for looking at larger pathogens such as Anchor worm (Lernaea) and Argulus, or fish lice, and any larger objects. If you look closely at this picture, (or right click and open picture in a new tab.) you will see there is corrosion from the salty water that came in with the samples. This microscope is well over 20 years old, but it could have lasted anopther 20 years if it had been maintained correctly. RIGHT: I use the dissecting microscope to look at larvae as well as pathogens. The jade perch larvae on the right are 5 days old. you can see their stomach is full of food.
On the right is a YouTube video of our larvae hatching under the dissecting microscope.	click to view

The PERCH MAN ABN 42 065 149 145

Click to download Jade Perch Description and History PDF.

CLICK TO READ ABOUT MY BREEDING PROGRAM

 

The PERCH MAN ABN 42 065 149 145

MURRAY COD 

 

How big do they get ?

This species can easily reach more than 100 pounds. That's over 45 kg.
The largest Murray cod recorded, in 1902, weighed about 113.5kg, that's over 250 pounds.

Australia has a number of freshwater cod species which all look very similar, however the species from the Murray Darling River Basins is the one widely produced in Australia. It is a popular aquaculture species, especially in cooler climates.

 

The PERCH MAN ABN 42 065 149 145

My contact details are here

Please note that any reference and or research to, or about silver perch, will mostly also apply to jade perch.

The following is a list of knowledge resources containing references to professional research, videos of conference presentations, videos with useful information, and experiences from various resources about aquaculture and Australian native species in general.

Unpacking fry and fingerlings that have been packed using modern methods, at very high commercial densities. If you do not follow these instructions your fish will almost certainly die within minutes of unpacking.

YouTube unpacking procedure play list here

Watch this videos while reading the following explaination of each step.

UNPACKING PROCEDURE IN DETAIL

You will need

1. Two buckets of about 10 litres each. 20 litre buckets are OK but it is best if one is 10 litre.
2. Plastic bags that will hold at least 30 litres
3. Large rubber bands
4. One industrial oxygen cylinder with regulator and trigger
5. Common plain salt. (Not table salt as this may have additives.)
6. One teaspoon
7. P.H. meter
8. One fine net about 12 inches

STEP 1.

Prepare a bag of water with a heaped tea spoon of salt. Allow the salt to dissolve perhaps by giving the bag a bit of a shake before adding the oxygen. The water should not have a P.H. higher than 7.2. Neutral P.H. is best. (7.0) Place the bag in one of the buckets.

Place the net over the top of the second bucket to be ready to pour the fish into.  

STEP 2.

STEP 3.

Remove the rubber bands from the goose neck of the bag.

Repeat this process for every bag of fish in the shipment. After at least one hour, but not more than 2 hours, go to step 4.

Step 4.

Click this link for the most resent on Diagnosis, treatment & prevention of the diseases of the Silver Perch HIGHLY RECOMMENDED READING ! Applies equally to jade perch !

Aquatic Plant Remediation of Waste Water in a Partitioned Aquaculture System. 

Click to view video (Duration 16 minutes.)

What should a commercial perch pond look like? Click for a 6.5 minute video.

Download PDF of this work: Performance, welfare and production strategies for the cage culture of silver perch

This short video shows how to use floating cages on a large farm water storage to grow perch. (Duration 3.5 minutes) 

NOTE: Jade perch are well suited to cage culture methods. In fact commercial growers have experienced better results with jade perch in cages, tanks, and partitioned aquaculture systems.

Therefor this video is also of particular interest to jade perch growers.

Click to view video (Duration 24 minutes)

 ALL FINGERLING PRICES ARE HERE

To order email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Delivery costs/options are near the bottom of this page

SLIVER PERCH 

AVAILABLE NOW

• 30- 49 fish ---      $2.42 each
• 50- 99 fish ---      $2.20 each
• 100-500 fish ---   $1.65 each
• Over 500 fish --- $1.21 each

JADE PERCH 

AVAILABLE NOW

• 30- 49 fish ---      $2.42 each
• 50- 99 fish ---      $2.20 each
• 100-500 fish ---   $1.65 each
• Over 500 fish --- $1.21 each

 

Commercial information about Australian perch see the members area

GOLDEN PERCH 

• 30 - 49 fish --- $2.97 each 
• 50 - 99 ---        $2.75 each
• 100 - 500 ---    $2.53 each

MURRAY COD SOLD OUT

• 10 - 20   --- $5.00 each
• 20 - 50 ---      $4.00 each
• 50 - 100 ---    $3.00 each
• 100 - 1,000 - $1.80 each

Your fish will come from Australia's most experienced breeder and live fish shipper

• Over 40 years experience shipping live fish
• Best quality fry
• Managed genetics for fast growing qualities
• Breeders sourced from the best growers in Australia
• Genetics managed using wild caught jade perch
  

FREIGHT AND DELIVERY INFORMATION

Fry and fingerlings can be shipped almost anywhere in the world

DOMESTIC CUSTOMERS delivery options

When and why I do or do NOT guarantee live arrival.

More shipping information

EXPORT CUSTOMERS

For almost 40 years I regularly ship to many countries around the world, including, Malaysia, Mainland China, Taiwan, Europe, Singapore, Philippines, Hong Kong and the United States. 

For export strictly commercial quantities with a minimum value of au$3,000

For detailed information about growing jade perch and managing their health see the members area.

Click below for YouTube videos about jade perch wild fish collecting

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The PERCH MAN ABN 42 065 149 145

HOME  

Click to download Jade Perch Description and History PDF.

For detailed information about jade perch go to the members area click for more

Jade Perch, (Scortum barcoo) come from an area of Australia known as the Lake Eyre Basin. Here, the water does not drain into rivers that end up in the ocean. All the rain that falls in this region drains inland, eventually reaching Lake Eyre, provided there is enough rain to make it that far. This is a huge area. Some of the catchment reaches up into tropical parts. Occasionally the remnants of a cyclone, in the form of a tropical depression, reach down to the top end of the catchment. This sort of event can result in large amount of rain flooding vast inland areas of country. For the fish in the waterholes of the Lake Eyre Basin such events create a massive explosion in the food chain. Mass spawning occurs and the cycle of fish life starts again.

Jade perch, (Scortum barcoo) only occur naturally in this area of Australia. The best candidate for aquaculture may quite possibly, only be the one from the Barcoo River. No other place in the world. Do they occur naturally in any other country - NO !

River basins of Australia with the Lake Eyre Basin in Red.

SEE jadeperchman on YouTube

Click this link for a 10 minute YouTube video of the trip to the Barcoo River. This is part 1 of the Jade Perch Story

Click for part 2 of the jade perch story

Click this link for a short YouTube video of the country on the way to the Barcoo River.

Click for a short YouTube video fly down the Barcoo River

Click for a short YouTube video of jade perch being collected from the Barcoo River

Transporting live fish video

For detailed information about jade perch go to the members area click for more

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The PERCH MAN ABN 42 065 149 145

For detailed information about jade perch go to the members area click for more Click to buy fingerlings  Click for recipes

Omega-3 the good oil !

Jade perch and silver perch - super foods

Australian JADE perch come from the Barcoo River in Queensland Australia!  

SEE jadeperchman on YouTube

The fat contained in these Australian JADE perch is the “good” fat, omega-3.

Way back in 1998 of over 200 seafoods tested by the CSIRO Jade Perch contained the highest levels of omega-3.
The second highest was the Swordfish, 1,667 milligrams of the good oil to every 100 grams.
Australian JADE Perch, from Queensland contained an incredible 2483 mg/100gm of omega-3 oils. Silver Perch had 792 milligrams per 100 grams.

The marketing name, "JADE perch" was chosen because of the distinctive greenish, (JADE) colour displayed by the fish as the light catches the dorasl area scales. Jade also suggests something of value, and valuable they are. They eat very well and have a firm, slightly flaky flesh.  
The fish come from a very hostile environment. Fish in Australian rivers must be able to cope well with the “feast and famine” nature of the rivers systems in Australia. These rivers can be dry for months, even years. Large water holes are the surviving refuge for many species of Australian native fishes, including Australian JADE perch. The fish in these water holes predate on each other for survival. After flooding the natural food supply for these fish is abundant. This glut of food is a contrast in the extreme compared to a drought situation where the fish will find getting a feed very difficult. Also during winter (usually the dry season) the fish are inactive and probably rarely feed. The stored fat will be used to help the fish survive in these situations. This is the Omega-3 fat humans need to thrive.

The following is adapted from an article written by Bruce Sambell for the Aquaculture Association of Queensland INc. Newsletter November 2000, author Bruce Sambell.”

SILVER PERCH KNOCKED OFF IT’S PERCH
BY BRUCE SAMBELL
In 1998 the CSIRO completed their fatty acids analysis of JADE perch, and guess what, the levels of Omega-3 content in Australian JADE perch are higher than over 200 species tested. This means that the Omega-3 content of our farmed JADE perch is the highest of over 200 Australian seafood's to undergo these tests. This testing was conducted at the CSIRO Marine Research Laboratories, Hobart as part of an FRDC project 99/331.
Silver perch had already undergone tests for it’s Omega-3 levels, however some doubt had been cast as to whether the fish tested were in fact silver perch or possibly Welch’s perch crossed with silver perch. The CSIRO subsequently confirmed the previous results. The samples were provided by the Government Research Facility in Grafton New South Wales.
Omega-3 results for Silver perch and JADE perch showed that JADE perch has 11.1% Omega-3, compared to Silver perch with 9.9%. Both species have excellent levels of omega-3.
JADE perch oil in the flesh, 24.1% compared with Sawfish with 1667mg per 100g.
There are also some differences in the other “oils”. Some are higher in Jade Perch, some are lower, but all are very good overall!

What about this stuff (omega-3) ? What’s so good about it? Well it seems it really can help you live longer. It has benefits to human blood vessels, helps protect against heart rhythm disorders, may even help protect against some forms of cancer. The list goes on, infants brain and retina function and development my also benefit, as well as reduce coronary heart disease, high blood pressure and rheumatoid arthritis.
Our Perch also contains lower levels of cholesterol than chicken, beef and lamb! Not even alternative products such as chicken, beef and lamb have anywhere near the levels of omega-3. JADE perch has 10 to 100 times more omega-3 than these more traditional food products.
Here are some quotes from the CSIRO,
“the unique nutritional benefits of marine oils come from the effects of their long chain omega-3 polyunsaturated fatty acids, and particularly DHA and EPA.
“the body can only make small amounts of these fatty acids and therefore we rely on dietary sources...
“ Australian fish have higher levels of the beneficial fatty acid DHA than fish from northern hemisphere waters.
“Other beneficial oils present in seafood
(a term which includes farmed fish ...) include omega-6AA which is important for growth and seems to play a role in our general good health and well-being.
Omega-3 found in Australian JADE perch...
Reduces Aggression. You are less likely to express stress-induced aggression if your brain is under the influence of fish oil, according to Japanese researchers. In a new double-blind test of 41 adult students, those taking 1.5 to 1.8 daily grams of DHA fish oil for three months did not become more socially aggressive at a time of severe mental stress: final exams. In contrast, students taking a dummy look-alike capsule showed significant jumps in social aggression, as measured by psychological tests. This effect on stress may help explain how fish oil prevents heart disease. Stress hormones triggered by hostility and anger can constrict arteries and accelerate the formation of blockages, research shows; fish oil may suppress the release of those hormones.
Stimulates young minds. Foetuses and infants must get sufficient omega-3 oils for optimal brain development, says William Connor, Oregon Health Sciences University. In one telling study of premature infants, those fed breast milk had 8 points higher I.Q. at age 8 than those fed standard infant formula. Connor credits breast milk's higher amounts of DHA for that superior intelligence. In infant rhesus monkeys deprived of omega-3-type oils, Connor found severely impaired visual acuity and behaviour indicative of a neurological defect. Autopsies revealed abnormalities in brain cells. Connor advises pregnant women to eat fish a couple of times a week, especially during the last trimester, the time of greatest foetal brain growth. And breast feeding is preferable to infant formula, he says.

Blunts Brain Damage? Fish oil may eventually be proved to lessen alcohol-induced brain damage, Salem says. He explains that excessive alcohol depletes brain levels of omega-3's -- DHA in particular -- which leads to neurological damage and impaired vision. He put experimental animals on high-alcohol, low omega-3 diets for six months to three years. They suffered severe losses of DHA in brain cells and detrimental changes in brain functioning. Some scientists speculate that fish oil also may have a protective role in degenerative brain diseases leading to memory loss and dementia. The brains of deceased Alzheimer's sufferers, for example, show low levels of omega-3 fats.
Food for thought ! ?

Reference: 

CSIRO Marine Research 2002 FRDC Project 1999/331 2002 B.D.Mooney, P.D. Nichols, N.G. Elliott 

The findings are published in a booklet titled...Seafood The Good Food II 

Page 51 of that booklet shows the list of oils contained in Scortum Barcoo (which is commonly known as Jade Perch.)

Total fatty acids = 15785 (per 100g)

of that,

Total saturates = 5437

Total monounsaturates = 5267

Total polyunsaturates = 4938

Total (n-3) = 3869

Total (n-6) = 667

Click for CSIRO report

Second report comparison jade perch and Murray cod. Note jade perch are refeed to as striped perch.

And . . . apart from all that . . . they make a great meal. As Theodore Pung from Singapore can confirm. 

To open images, right click - open in new tab.

For detailed information about jade perch go to the members area click for more

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The PERCH MAN ABN 42 065 149 145

 SEE jadeperchman on YouTube

The PERCH MAN ABN is 42 065 149 145

Contact details at bottom of page.

Click for full details. Aquaculture consulting

In 1999 Bruce was made “Patron” for ANGFA ACT., Australian New Guinea Fishes Association.
In 2000 he was appointed to the, “working group” for the Conservation Genetics Inventory Project for Murray Darling River Fish.

Bruce also built the Ausyfishfish farm from 1988.

WARNING Beware of the imposter fish click for details

The members area has detailed information about jade perch, including growing and disease management  click for more

Three levels of consulting services are available to clients starting from au$25.00 

level 1.  Members area of this web site from au$25.00 click for more details. 

Level 2 Site visit. au$480.00 per day plus expences. Available to existing and potential growers of Australian freshwater fish. Advice is based on over 40 years experience and hands on practice. Many clients use this as an opportunity to have staff trained in better fish handling practices, including how to condition brood fish and spawn Australian perch. click for more details.

click for more details.

All my contact details are here