Special Freshwater Fish

Australia was once partially covered by an inland sea and during this time, many of the Wet Tropics fish arrived from elsewhere. When the sea receded, these species became isolated in northern rivers and streams and continued their evolution independently. One such isolated relic species is found only in the Bloomfield River.

The Bloomfield River Cod (Guyu wujalwujalensis) is very ancient and very rare and its survival may be due to the fact that a similarly sized species with a similar diet, the Sooty Grunter, does not exist in the Bloomfield River. Were the Sooty Grunter (Hephaestus fuliginosus) to be translocated (deliberately or otherwise) into the Bloomfield River upstream of the Bloomfield Falls, it might spell the end of the Bloomfield River Cod, a species which has been around for roughly 60 million years!

Sometimes, the best things come in small packages. Tiny Gertrude's Blue-eye (Pseudomugil gertrudae) is one such small package. Only 30mm (1 ¼ inch) long, this pretty fish has rows of spots along its side and throughout the dorsal, anal and tail fins. It prefers water bodies that are densely vegetated and swamps and lagoons are a favourite. As there is tremendous pressure to develop many of the north Queensland coastal wetlands, the Gertrude's Blue-eye will be a species to keep a watch over to ensure that it doesn't become a newcomer to the threatened species list.

The Barramundi (Lates calcarifer) is one of the most well-known fish in Australia. Barra are the stuff that anglers' dreams are made of: a sporting catch, lovely to eat and plenty of it at a maximum of 60kg (132 pounds). The demand for this fish has sparked a multi-million dollar aquaculture and commercial fishing industry. However, it is unfortunately an aggressive predator of endemic species.