Silver perch
Bidyanus bidyanus
Also known asBidyan · Grunter
Water parameters
Minimum tank: 300 L per individual at harvest size.
Feed and growth
- Feed protein
- 32% target
- Daily feed (warm)
- 1.30% of body weight
- Daily feed (cool)
- 0.60% of body weight
- Max density
- 45 g per litre
A 1000 g adult eats about 13.0 g of feed per day at optimum. 10 fish at adult size: ~130 g daily.
Legality
Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.
| Jurisdiction | Status | Notes |
|---|---|---|
| New South Wales | legal | Native species; no permit required from licensed hatchery fingerlings verified 2026-05-13 |
| Victoria | legal | verified 2026-05-13 |
| Queensland | legal | verified 2026-05-13 |
Unlisted jurisdictions default to "check local regulations".
Origin and habitat
Native to the Murray-Darling River basin in southeastern Australia. The species (Bidyanus bidyanus) is a medium-sized freshwater fish reaching 40–50 cm and 2–4 kg in the wild, though culture harvest size is typically 400–800 g. Silver perch inhabit warm, slow-moving rivers, billabongs, and floodplain lakes. The flesh is white, moist, and mild-flavored, though it can develop an off-flavor (earthy or muddy taste) in stagnant or algae-rich water, which is the species' main market limitation. Wild populations have declined due to river regulation, habitat loss, and competition from introduced species. Silver perch is one of the most commonly cultured native freshwater fish in Australian aquaponics.
Climate and outdoor ponds
- Climate
- subtropical (tolerates mild cooling)
- USDA zones
- 8–13 (winter low around -12°C or warmer)
- Heating needed
- yes
- Cooling needed
- no
Care notes
A warm-water species well-suited to Australian aquaponics, with faster growth than golden perch or Murray cod and broader temperature tolerance than barramundi. Optimal temperature is 23–28°C, but the species tolerates 2–35°C, surviving Australian winters without heating in most mainland locations. Growth: 400–800 g in 10-14 months on commercial pellet (32-40% protein). FCR is 1.5-2.0, competitive with Nile tilapia. Stocking density: 15-30 g/L. Silver perch are schooling fish that tolerate crowding better than the predatory Murray cod or golden perch, making them suited to higher-density tank culture. They accept pellet feed readily when trained as fingerlings, with good feed conversion. Water quality: DO above 4 mg/L, ammonia below 1 mg/L, pH 6.5-8.5. The species' main culture issue is off-flavor: silver perch accumulate geosmin and 2-methylisoborneol (MIB) from blue-green algae in the water, giving the flesh a muddy or earthy taste that consumers reject. In aquaponics systems with clean, well-filtered water and low algal load, off-flavor is significantly reduced compared to pond culture. Purging fish in clean, flowing water for 3-7 days before harvest eliminates residual off-flavor in most cases. Fingerlings are widely available from Australian hatcheries, with supply peaking in spring and summer. Legal to culture across eastern Australia without special permits. For Australian aquaponics operators who want a native species combining fast growth, good cold tolerance, and schooling behavior suited to tank culture, silver perch is the most balanced all-round choice.