the brisbane river cod was a unique form of "maccullochella" cod that occurred naturally in the brisbane river system, an east coast river system in south east queensland, australia. their exact taxonomic status is not known, but based on several genetic studies it is suspected that brisbane river cod were a species intermediate between eastern freshwater cod ("maccullochella ikei") of the clarence river and richmond river systems in northern new south wales and mary river cod of the mary river in central queensland.