Australian bass (Percalates novemaculeata)

AUSTRALIAN BASS – NATIVE AUSTRALIAN FISH

Other names: Freshwater Perch

Minimum volume requirement: fingerlings can be raised in an unheated aquarium, full-grown individuals do best in a large outdoor pond/dam.

Size: 30cm (can reach up to 60cm)

pH: 6 – 7.5

Temperature: 10°C – 26°C

Life span: 15 – 20 years

Australian BASS

Description

A medium-sized freshwater fish averaging 20 – 30cm and 1kg. The largest individuals measured up to 60cm and 3.5kg. Dark greenish grey on the back/upper body with lighter sides and a silver/whitish belly. The lower jaw protrudes past the upper jaw. Australian bass have a large, strongly spiny dorsal fin and gill covers with extremely sharp, flat spines that are capable of delivering a nasty cut.

Distribution

The Australian freshwater bass are found in coastal rivers from the Mary River in QLD south to tributaries of the Gippsland lakes in VIC. Distribution reports are often however dubious at best due to frequent confusion with the very similar Silver Perch. Bass populations have declined significantly over the years as access to approximately half of their total potential habitat has been obstructed by dams and weirs (which is particularly significant due to the highly migratory nature of this species).

Breeding

Males reach sexual maturity at about 18cm (2 – 4 years of age). Females reach sexual maturity at about 28cm (5 – 6 years of age).

Bass are catadromous (migrate downriver towards the ocean to spawn) breeding from May to August in brackish waters. Females are capable of producing anywhere from 440,000 to 1.5 million eggs at once, and may spawn multiple times in one season. Eggs will sink to the bottom of the estuary hatching 2-3 days after fertilisation as larvae approx 2.5mm long.

Diet

These are carnivorous fish feeding in the wild on crustaceans, insects, tadpoles, worms and smaller fish. In captivity, bass can thrive on high-protein pellets.

BASS IN PONDS

Keeping bass in ponds is becoming a very common practice though one needs to be mindful of mixing them with smaller species, especially in a small-sized pond. They are no longer just kept for the table but as popular backyard fish stock. Silver perch and koi are the best fish to mix with bass due to their large size.

BASS IN DAMS

Australian bass are an excellent addition to dams, especially if you are looking for recreational fishing (or even fish for the plate!). Fingerlings and juveniles are often available for purchase directly from hatcheries allowing you to constantly restock the population.

BASS IN AQUAPONICS

The exact growth rate of bass for aquaponics will vary depending on the size of the tank, food quantities and the species you have chosen. But, the average bass should grow between 5 – 20cm in the first year. Within 2 years they will reach an adult length of 25 – 30cm. It is possible to increase the rate of growth by feeding your bass a protein rich diet.

A temperature of 18°C – 24°C will ensure eggs hatch successfully. Within two days of fertilisation eggs will begin to hatch. Fingerlings grow quite quickly, they should reach 5cm within their first 6 months of life.

Bass can tolerate relatively large changes in their environment without any adverse effects, though of course, significant changes are likely to alter their behavior slightly. This makes them an excellent choice for those who want to start an aquaponic system. Bass and silver perch will happily mix.

Australian bass (Percalates novemaculeata)