Australian bass

Water parameters

Minimum tank: 400 L per individual at harvest size.

Feed and growth

Feed protein

42% target

Daily feed (warm)

1.10% of body weight

Daily feed (cool)

0.60% of body weight

Max density

35 g per litre

A 700 g adult eats about 7.7 g of feed per day at optimum. 10 fish at adult size: ~77 g daily.

Legality

Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.

Unlisted jurisdictions default to "check local regulations".

Origin and habitat

Australian bass, Percalates novemaculeata (long known as Macquaria novemaculeata), is a percichthyid native to the coastal river systems of eastern Australia, ranging from the Mary River in southern Queensland south to the Gippsland Lakes in Victoria. It is a prized recreational sport fish, valued for a hard fight on light tackle and for clean, firm, white flesh. Wild fish are catadromous: adults live in freshwater rivers and impoundments and run downstream to brackish estuaries to spawn in the cooler months, roughly May to August, on flood flows, releasing pelagic eggs. River fish commonly average around 0.4 to 0.5 kg and 20 to 30 cm, with the largest reaching about 2.5 kg and 55 cm in southern waters and around 3 kg and 60 to 65 cm in the north; the maximum reported age is 22 years. In culture the fish can be raised entirely in fresh water. It grows slowly next to barramundi and silver perch, which limits its commercial appeal, but it suits native-species aquaponics in the cooler southeast.

Climate and outdoor ponds

Climate

temperate (handles seasonal swings)

USDA zones

7–11 (winter low around -18°C or warmer)

Heating needed

no

Cooling needed

no

Care notes

A temperate to subtropical native that fits cooler Australian aquaponics, comfortable across roughly 10–30°C with growth best in the low-to-mid twenties. Its main drawback for culture is pace: it grows slowly compared with barramundi and silver perch, and published farmed performance data are thin, since it is only a minor aquaculture species. Expect figures in the range typical of carnivorous native percichthyids: a high-protein pellet of about 40 to 45 percent protein and feed conversion somewhere around 1.5 to 2. The fish is native and can be cultured in most eastern states without the regulatory hurdles that apply to non-native species, though Victoria requires a permit. Fingerlings come from several Australian hatcheries but supply tends to be seasonal, tied to the winter spawning run. Australian bass are ambush predators that will take smaller fish, so regular size-grading is needed. Keep dissolved oxygen above about 5 mg/L, ammonia low, and stocking moderate. The flesh is excellent, which makes it a strong choice for personal-consumption systems in the southeast even if it never matches faster natives on yield.

Further reading

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