| The Murray Cod is a moderately long fish with a deep body. They have small eyes and a large mouth with a protruding lower jaw. Their colour ranges from cream to an olive-green with dark grey to greenish-brown mottling on the head, back and body. They have a white belly and their fins are edged in white. Murray Cod can grow up to 1.8 metres in length and weigh as much as 114 kg, though it is more common to see one up to 70 cm and weighing less than 10 kg. Larger fish are now very rare.
Murray Cod prefer to live in slow flowing water and favour deeper areas around submerged logs and boulders as well as undercut banks and overhanging vegetation. The species can be found in the waterways of the Murray-Darling River basin in Queensland, New South Wales, Victoria and South Australia. It has been introduced into lakes and dams in New South Wales and Victoria. Once found in great numbers, Murray Cod populations have declined severely. This is due to severe overfishing, river regulation and habitat degradation. Maccullochella peelii is now listed as a threatened species.
Murray Cod are apex predators. They eat molluscs, crustaceans, frogs, other fish, turtles, water dragons and even some small land animals such as mice and snakes. They have even been known to prey on ducks and cormorants.
Their spawning season is Spring. The season begins with the fish migrating upstream - one fish is known to have migrated a distance of 120 km! Actual spawning is initiated by pairing up and courtship rituals. During this courtship, a spawning site is chosen - a rock or inside a submerged log - and the site is cleaned. The female then lays a mat of 10,000 to 100,000 eggs (the bigger the fish, the more eggs she will lay), which stick to the spawning surface and the male then fertilises them. The female leaves and returns to her home territory. The male stays and guards the eggs until they hatch. Depending on the water temperature, this can be between one and three weeks. The father will continue to protect the larvae for another week or so until they disperse and then, he too, returns to his home territory downstream. Murray Cod reach sexual maturity usually around five years of age. This species is one of the longest lived of Australian freshwater fishes. It is thought that some of the largest Murray Cod may be over seventy years old.
The Murray Cod features in an Aboriginal legend about the creation of the Murray River and the other native fish that live there. You can read the story here: Dreamtime stories.
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