Freshwater Catfish (Tandanus tandanus)

tandanus catfish

NATIVE AUSTRALIAN FISH

Other names: dewfish, freshwater catfish, eel tail catfish

Minimum volume requirement: 500L (100L is ideal)

Size: 80cm

pH: 6.5 – 8

Temperature: 15°C – 26°C

Life span: 8 years

Tandanus catfish Description

The tandanus catfish is an eel-tailed catfish, with a stout body, large head and downturned mouth. These fish have been known to grow up to 90cm long and weigh 7kg, though specimens over 2kg are very rare. Four pairs of barbels are located around the mouth. Tandanus cats have a strongly serrated spine and pectoral fins very capable of cutting human skin. These fish are scaleless and smooth with dark grey/brown skin fading to a creamy white belly.

Males and females can be distinguished at around 1 year of age by the shape of the urinogenital papilla, which is triangular in females and cylindrical in males.

Distribution

Tandanus catfish are widespread throughout the Murray-Darling system in inland QLD, NSW, VIC and SA. They are also present in many coastal rivers of eastern Australia from Sydney to Cairns.

Breeding

Tandanus spawn when temperatures rise during spring and summer. The number of eggs increases with size, ranging from about 2800 to 20,600 eggs in females between 390 and 530mm long. They build a circular nest, around 60-200cm in diameter, from pebbles and gravel.

during courtship, both male and female circle and weave above the nest. The female then arches her body, agitates her pelvic fins and releases the eggs about 30cm above nest. They are spherical, non-adhesive and a light greenish yellow in colour. Males fertilises eggs, which sinks to the bottom, settling in gravel of nest. One of the adults, usually the male, remains at nest until the eggs hatch in about 7 days. The larvae are about 7mm long when they hatch, and barbels appear on the young after about 3days. They grow quickly reaching 90mm by their first winter and 500mm in their sixth.

Diet

These fish are carnivorous, young catfish feed on Zooplankton and small insects especially chironomid midge larvae. Catfish longer than 100mm also eat small fish such as western carp, gudgeon, blue eyes, rainbows. In captivity this diet can be supplemented with high protein sinking pellets.

Tandanus catfish in ponds and dams

These catfish are only suited for large ponds and dams. In aquariums they need to be by themselves or with larger species of fish. In ponds, Tandanus need to be with larger fish and not with ‘frog friendly’ fish. This is because they eat small fish due to the fact that they are highly predatory nature. If the pond is bigger though (20000 litres and above), they can be introduced with smaller species because of the large space. Same thing applies for Dams, due to the large space, they can be introduced as a way of balancing the ecosystem.

Freshwater Catfish (Tandanus tandanus)