Fishes

It is of little surprise that the Wet Tropics contains one of the richest and most diverse freshwater fish faunas on the Australian continent with about one third of Australia’s 190 or so species of endemic freshwater fishes having been recorded. However, it was thought that few were endemic, and only in recent years has extensive research been carried out on freshwater fishes from this area.

It now appears that several forms of Rainbowfish may be undescribed endemic species. Some are confined to small rainforest creeks where they are unable to move downstream because of waterfalls. Gobies are common throughout the area, but are often notoriously difficult to identify from each other. They usually lurk on the bottoms of flowing streams. Recent research has shown that there are probably numerous undescribed species of gobies in north-eastern Queensland.

Freshwater fish fauna range in size from the tiny Perchlets and Rainbowfish a few centimetres in length to the large carnivorous Barramundi which can grow to 1.8 metres and 60 kilograms in weight. The high altitude headwaters of streams are often devoid of fish. Here a variety of yabbies and crayfish may be found.

The Barramundi which is distributed throughout tropical Australia, is fairly common in the Wet Tropics with a good population in the Daintree River and nearby streams. It inhabits mostly the middle and lower reaches of streams as well as lagoons. A popular eating fish and prized by sport fishermen, it has an intriguing sex life. Each begins life as a male and later, between three and five years, changes its sex to become female!

There are many interesting fish to be found in the Daintree - Jungle Perch, Butterfish, Long Tom, Gudgeon, Blue-eye, Catfish, Freshwater Bream, Spangled Grunters and Mouth Almighty which has a voracious appetite for almost anything that moves - as long as it is smaller than itself! Archerfish are common. These remarkable fish can shoot a high pressure jet of water with exceptional accuracy, knocking an insect off a branch or leaf a metre or so above the surface.