Kangaroo Syndrome

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The PERCH MAN ABN 42 065 149 145


Why I call it Kangaroo Syndrome, I refer to the lack of growth when perch 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.


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. It does NOT happen in open earth ponds.

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.

Silver perch in Singapore Click picture for video