Once widespread and abundant in the Murray, Lower Darling and Murrumbidgee river systems in southern NSW and northern Victoria, Murray Hardyhead is now considered one of Australia's most threatened species. They are listed as critically endangered in NSW.
This small fish (3 – 8cm) usually schools near or among aquatic plants on the edges of wetlands and slow-flowing lowland rivers. Usually located in marginal saline habitats (e.g. isolated wetlands), but you may also encounter them in farm dams, irrigation channels, ponds or even tanks which held water in the recent drought.
Other closely related Hardyhead species, particularly Un-specked Hardyhead which is a common species.
A Murray Hardyhead (left) and an Un-specked Hardyhead (right)
Murray Hardyhead have circular scales that are irregularly arranged with pigmentation on the edges. Un-specked Hardyhead have diamond-shaped scales arranged in rows with pigmentation throughout.
Close-up images of Murray Hardyhead scales (left) and Un-specked Hardyhead scales (right).
If you see a Murray Hardyhead, take a photo focusing on the scales and report the sighting. The scales are critical for species identification.