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AUSTRALIAN PERCH

^{The first commercial supplies of golden perch fingerlings were supplied to grow-out farms in Australia during the 2003-4 season. They 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 is using large round Polly tanks. In his words the fish are described as "..the barramundi of the inland".}

                 
^{Above - large fish are great baked in the oven}
                  

^{For many years  Ausyfish have selected brood fish for their fast growing qualities. A number of generations of fast growing fingerlings have been retained and grown-out. From the largest of these grown-out fish we have chosen our breeders. With improvements in diet and genetic selection we believe we are offering the grow-out sector a potentially faster growing fish. The poultry industry now grows a chicken for the table in a few weeks, once this took about a year. Their improvement in growth performance was a result of genetic selection and diet. We hope to see similar results within our industry. These fingerlings are now highly sort by growers through out Australia.} 

^{Jade Perch}

^{Jade Perch (Scortum Barcoo). Marketed under the name Jade Perch are also produced in large numbers by Ausyfish. We are arguably the largest producer of these fish. Jade Perch is a new species to the developing freshwater fin-fish grow-out sector.} 

^{Jade Perch are a proven performer in recirculating aquaculture systems. Jade Perch also grow very well in open ponds. Jade Perch really seem to grow very fast compared to Silver Perch. Some growers have even said, twice as fast.} 

^{Ausyfish produces fingerlings, and egg-sack larvae, and fertilised eggs for customers world-wide. One of the most popular products is egg-sack larvae or fertilised eggs. Click for more information about this product.}

^{What is a runt?}

^{This is a fish that does not have the genetic potential to reach the normal full size of the species. For example, if a perch normally has the genetic potential to reach a size of 3 kilo, but cannot grow because of the lack of the normal requirements, such as sufficient food or temperature, its growth will be interrupted but not stunted permanently. It still has the genetic potential to reach its 3 kilo once the fishes missing requirements have been restored. A true runt however is genetically deficient. It does not have the potential to reach the normal size of 3 kilo. It is in fact a dwarf. Dwarfism is extremely rare in fish as it is in most animals. Therefore to say that a large percentage of fish contained within one pond are runts is inaccurate. The real problem lays elsewhere!}

^{Pond Weaned}

^{Many growers have experienced some considerable variation in fish sizes within a pond of fish of the same age.  Part of the cause is highly likely to be found in the weening of the fingerlings.} 

^{Most hatcheries in Queensland produce their  perch fingerlings in “plankton ponds.” In a plankton pond fingerlings grow to market size (4-5cm) in an environment where they develop entirely on natural food.} 

^{This is a method used for almost two decades to produced fingerlings for the stocking of waterways within Queensland. (For freshwater angling.)} 

^{At Ausyfish we have specialised in the production of fingerlings specifically for the grow-out sector. Our fingerlings are fed in ponds,  commercial fish foods from the first few weeks. This means our fish are POND WEANED.}

      ^{Above: A typical fingerling pond.}

^{Weaning of fish can be done after they have been removed from a plankton pond and placed in a large tank. The fish will quickly accept artificial feeds in this environment. But what can happen when they are returned to a pond for grow-out is that many of the fish will recognise this environment as one where they eat, “natural food."} 

^{Fish that have been weaned in the pond from when they are very young, just two or three weeks old, will see artificial food as their normal food. This will result in less of the fish failing to grow well.}                  

^{Perch fingerlings are weaned in ponds. From about day 10-14 we start feeding our fingerling ponds. Normally by about day 20-25 the fingerlings are about 20mm and feeding on commercial fish food in the pond. They are fed daily until they are ready to harvest. The diet used is Ridley Aquafeed "Native Fish Starter Dust". This product contains 52% crude protein, 12% crude fat, and 1.6% crude fibre.}

^{Once fingerlings are delivered they are ready for a larger diet. We recommend you contact GroBest.  You can contact Grobest by calling 1800 005 434. (Local call cost.) Grobest will supply any quantity, even a single bag.}

^{In a final attempt to minimise the size variation of the grown fish, we pass the fingerlings through a grader. This allows any fish that are significantly smaller to be separated from the fingerlings intended for delivery to the grow-out farmer.}      

^{Click for information about fingerling prices}

^{When the fish is filleted and compared to a Silver Perch fillet, we have noticed some differences.
The Silver Perch has a more fibrous flesh and the Jade Perch has a slightly "flakey" flesh. The Silver Perch has a delightfully tender, melt-in-the-mouth quality. The jade Perch also posses this quality, but is a little firmer.}

^{Flesh recovery is about 50%, depending on the size of the fish.}

^{It is rare to find fat in the actual fillet of a Silver Perch, however it is common to find fat between the "flakes" of a Jade Perch fillet. This fat is not the white fat found in the body cavity but a translucent, jelly like fat. When the fillet is cooked it is relatively easy to cook out this fat as it melts in the pan easily. Having discussed the fat in these perch we should also say that the fat is one of the major selling points about our Perch.} 

^{The fat contained in these Perch is the "good" fat, omega-3. Follow the link for details of the omega-3 levels found in Silver Perch and Jade perch, and some of the benefits of omega-3. For the fish to readily use stored fat it is stored in the muscle tissue where it is needed the most. When fat is stored for easy use in the muscle tissue it is stored as omega-3. The fat within the body cavity, when tested had an omega-3content of 8.6% total fatty acids. This body cavity fat is less easy to use quickly and probably sustains the animal over long periods of so called famine.  Omega-3}

^{Left: a Silver Perch and Jade Perch of similar weight (750g.)raised under pond conditions. Note the different body shapes, also the spots on the Jade Perch. These spots, patches or marks, are different on every fish. The marks vary from fish to fish, and are different on each side of an individual fish.}  

^{WARNING:    There is another fish, the Scortum Hillii, commonly known as the Leathery Grunter. It is called the Leathery Grunter because of its incredibly tough eating quality. These two fish are very difficult for even he trained eye to tell apart ! If you were a grow-out farmer who had spent time and money to grow a fish that turned out to be the wrong species your reputation could be seriously damaged and your product would be worthless. Be sure to purchase your fingerlings from a reputable hatchery. The brood fish should be Scortum Barcoo from the Barcoo River system. This will ensure that you get the "good" eating fish.}  

Pictured right is a Scortum Hillii photographed immediately after capture from the Dawson River.

 

Po Box 324, Childers, 4660 (AUSTRALIA) Fax (61) (07) 4126 2221 Telephone (61) (07) 4126 2226

Jade Perch Pictures