Congolli

Interesting Info

• The Congolli is a small to medium-sized native fish found in southeastern Australia, including rivers and estuaries of South Australia, Victoria, Tasmania, and New South Wales.
• They are slender-bodied, with a mottled brown to olive colouring, a pale underside, and small dark spots across the body and fins — giving them excellent camouflage on sandy or muddy bottoms.
• It usually grows to around 10–20 cm (4–8 in), but some individuals reach 35 cm (14 in).
• They are part of the family Pseudaphritidae, which is unique because it contains only this one species worldwide — making the Congolli a true Australian oddity.
• Congolli are amphidromous, meaning they move between freshwater and saltwater during their life cycle. Adults live in rivers and estuaries, but spawning takes place in estuaries during winter, where eggs hatch into larvae that drift out to sea before migrating back upstream as juveniles.
• Their spawning migrations are well known in Tasmania, where large numbers of juveniles return upstream in spring — an important seasonal event for river ecosystems.
• Juveniles form schools and gradually spread upstream, often travelling tens of kilometres from estuaries into freshwater reaches.
• Congolli are opportunistic feeders, eating aquatic insects, worms, small crustaceans, molluscs, and tiny fish. At night, they often move into shallows to hunt.
• They are excellent at hiding, resting during the day among rocks, seagrass beds, and submerged logs, blending in with their surroundings.
• They are sensitive to river barriers such as dams and weirs, which block their upstream migration. Fish ladders and conservation efforts are helping restore their movements in some rivers.
• Lifespan is thought to be around 4–6 years, though some may live longer in undisturbed habitats.