Culture environment for silver perch

Silver perch are suited to aquaculture because of their high survival and rapid growth rates. Marketable fish of 400–600g can be grown in 10–12 months.

Pond systems

Commercial production normally occurs in purpose-built earthen ponds. The recommended pond size is 0.7–2.5m deep with a surface area of 0.1–0.5ha.

Prior to stocking, ponds are drained, dried and cultivated. They are then filled with water that has been passed through a filter screen.

Ponds should be easily drainable and slope to a concrete sump to help farmers harvest stock. Properly installed netting or placing nylon scarewire across the pond may prevent predation by birds.

Water temperature

Temperature tolerance ranges from 20oC to 35oC. Optimum growth rates occur between 20oC to 30oC, with negligible growth below 12oC.

Water quality

Although silver perch are able to tolerate poor water quality conditions, maintenance of water quality is necessary to achieve optimum growth rates.

Dissolved oxygen levels of 4mg per litre or greater encourage maximum growth and survival. Supplementary aeration (e.g. paddlewheel) is required at densities greater than 5000 fish per hectare and is essential for commercial production.

The excreted metabolic waste ammonia will limit production at levels greater than 0.1mg per litre and becomes lethal at 0.6mg per litre. Careful management of stocking densities and feed rates will prevent excessive ammonia concentrations.

Silver perch are able to tolerate pH levels between 6 and 10, with the desired range between 6.5 and 9.

Salinity levels of 5g per litre of sodium chloride are acceptable for long-term exposure and can be used to treat ectoparasite and fungal diseases.

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