Murray cod

Lore & Background

The Murray cod was first scientifically described by explorer Major Mitchell from the Peel River. Its scientific name honors early fish researcher Allan Riverstone McCulloch and the Peel River. For a number of years it was classified as M. peelii peelii to differentiate it from the Mary River cod, but as of 2010 the Mary River cod was raised to full species status (M. mariensis), reverting the Murray cod to M. peelii.

Murray cod populations have declined severely since European colonisation due to overfishing, river regulation, and habitat degradation. They once inhabited almost the entire Murray-Darling basin in great numbers but are now a listed threatened species. The species is long-lived, with the oldest aged specimen reaching 48 years, and larger historical specimens suggest they can reach 70 years or more.

Adult Murray cod are carnivorous, eating crustaceans, fish, and freshwater mussels. They spawn in spring, laying eggs in hollow logs or on hard surfaces, and exhibit a high degree of parental care. They are popular among anglers and in aquaculture, and are also kept as aquarium fish in Australia.

Reader's Guide

The Murray cod is ecologically significant as the apex aquatic predator in the Murray-Darling basin, Australia's largest river system. Its decline reflects broader environmental pressures from European settlement, including overfishing, river regulation, and habitat degradation. The species' long lifespan—potentially over 70 years—is an adaptation to Australia's variable climate, ensuring adults survive to participate in rare, exceptional spawning events linked to wet La Niña years. Taxonomically, the Murray cod has a complex history: early confusion with the trout cod led to name changes, and genetic techniques in the 1970s clarified the distinction. The species also demonstrates a pattern of speciation into lowland and upland forms, with related coastal cod species arising from natural river capture events across the Great Dividing Range. Its cultural importance to Australians and its role as a flagship for river conservation make it a key species in understanding and managing the Murray-Darling ecosystem.

Did You Know?

• The Murray cod is not related to Northern Hemisphere marine cod (Gadus species).
• The largest Murray cod on record was over 1.8 m (5.9 ft) and about 113 kg (249 lb).
• Murray cod can live at least 48 years, and possibly 70 years or more.
• The species was once found in almost the entire Murray-Darling basin but is now a listed threatened species.