The River Blackfish is found in a wide variety of freshwater habitats from fast-flowing mountain streams to sluggish lowland rivers, its main requirement being that of shelter in which to breed, hunt and hide.
Individuals prefer streams with plentiful cover, such as boulders, fallen branches and overhanging banks. Resting during daylight hours, fish move about at night feeding opportunistically on aquatic and terrestrial invertebrates, and occasionally small fish.
Mature adults breed during the spring and early summer, forming pairs shortly before they spawn in hollow logs, where water flow is reduced. Males actively guard the eggs, taking care to remove silt and detritus that may drift over. Without such care eggs can be quickly covered with sediment and slime, and soon die.
The River Blackfish is confined to south-eastern Australia, with population patches in southernmost Queensland, eastern New South Wales, easternmost South Australia, and much of Victoria and Tasmania.
It is adversely affected by the increased sedimentation of rivers and has consequently experienced a decline in the size of populations and the extent of its range, due to the alteration of rivers and streams.
The Blackfish family Gadopsidae is uniquely Australian, and appears to be a close relative of the Australian cods and basses, like the Murray Cod and Golden Perch.
Reaching a length of 60 cm in Victoria, the River Blackfish doesn't often get much longer than 45 cm-still, a respectable size for recreational anglers.