Their range encompasses northeast Victoria, southeast New South Wales and the Australian Capital Territory.

Originally two-spined blackfish co-inhabited many of these waters with Macquarie perch and trout cod.

[3] The species feeds mostly on aquatic insect larvae and terrestrial invertebrates, and occasionally other fishes and crayfish.

Larvae hatch after around 16 days and remain at the spawning site with the male parent for another 3 weeks.

Recent severe bushfires in south-eastern Australia (2003–2006), however, have filled many upland rivers with large quantities of silt, and infilled the interstices ("gaps") between larger rocks that two-spined blackfish normally use as a refuge from predatory trout species.