Congolli

The congolli is a slender, mottled fish, with a silvery-white underside. Its head is slightly flattened, with eyes positioned towards the top and the snout is pointed. It has two separate dorsal fins. The colour varies according to where it lives: it may be bluish, purplish or reddish-brown, marbled with greenish-brown above, and a yellowish white to silvery colour below. Juvenile fish have black saddles on their dorsal surfaces.

The largest adult measured is about 36 centimetres (14 in) long. Usually, adults grow up to 17 centimetres (6.7 in) long.

The congolli is found in fresh, brackish and marine waters around south-eastern Australia, including Tasmania, and is endemic to Australia. It lives mostly in slow-moving waters of estuaries, rivers and streams. Water temperatures in its habitat range from 5 to 20 °C (41 to 68 °F). This fish will inhabit areas with log snags, overhanging banks, and leaf litter.

Between late April and August, it migrates south to estuaries and sea to breed.

In 2017, congolli were recorded in five rivers on Kangaroo Island in South Australia for the first time, thanks to a project conducted by Department of Environment, Water and Natural Resources (DEWNR) and carried out by a number of citizen science volunteers.

Tupongs have made a recovery in the Glenelg River in south-western Victoria, after years of absence.

The congolli is a carnivorous ambush predator, and feeds on insects (especially in freshwater), fish, crustaceans (especially in estuaries), worms, molluscs, and other invertebrates.

Congolli are catadromous – they live in freshwater habitats as adults, and migrate downstream to estuaries to spawn. Adults migrate south to estuaries reproduce between late April and August. The larvae are carried out to sea, and slowly move upstream as they grow; the larger adults live furthest upstream.

Aboriginal peoples living in the area used to eat Congolli, and the flesh is today considered "excellent eating". However the fish are rarely large enough and no longer important in commercial fishing, although once a minor part of lower Murray fisheries.