The Northern River Blackfish (Gadopsis marmoratus) is a nocturnal, benthic freshwater fish native to southeastern Australia. It inhabits a variety of stream types, favouring areas with perennial flow and ample instream cover such as woody debris, aquatic vegetation, or boulders. An opportunistic carnivore, its diet includes aquatic insect larvae, crustaceans, terrestrial insects, and occasionally other fish. Spawning occurs from October to January when water temperatures exceed approximately 16°C, with males guarding the eggs in hollow logs or under rocks.