Silver perch

Quick facts

Adult size

40 cm, 1000 g typical harvest weight

Days to harvest

365 to 730 days from fingerling

Lifespan (max)

up to 25 years

Diet

omnivore

Temperature class

warm-water

Difficulty

beginner

Water parameters

Temperature range

15–30°C (optimum 25°C)

pH

6.5 to 8.5

Hardness

5 to 25 dGH

Minimum tank

300 L per individual at harvest size

Feed and growth

Feed protein

32% target

Daily feed (warm water)

1.30% of body weight per day

Daily feed (cool water)

0.60% of body weight per day

Max stocking density

45 g per litre of system water

A 1000g adult eats about 13.0 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 130 g of feed daily.

Legality

Aquaculture and possession rules vary by jurisdiction and change over time. This table reflects regulations as of the verified date on each row. Verify with your local fisheries or wildlife authority before stocking.

Jurisdictions not listed here default to "check local regulations". A non-listing is not a green light; rules in your specific county or municipality may apply.

Habitat and origin

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 classification

subtropical (tolerates mild cooling)

Outdoor pond zones (USDA)

8 to 13 (winter low around -12°C or warmer)

Heating in a temperate climate

Required for year-round operation

Cooling in a temperate climate

Not required

Zone bounds reflect year-round outdoor pond viability with no active heating. Anywhere outside the bounded zone, the species can still be kept in an indoor heated tank or a seasonally-managed system. Verify your specific microclimate, as a sheltered yard zone can run a half-zone warmer than the regional rating.

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.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else