Murray cod

The Murray cod is a giant, much-loved fish that lives in the rivers of eastern Australia. It is one of the largest freshwater fish in the whole country. Most grown-up Murray cod are already about as long as a bicycle, but the very biggest one ever found measured around 1.8 metres — longer than a tall grown-up is high — and weighed about 113 kilograms. That is heavier than two whole people!

This big fish is the top predator of its river home, which means it sits right at the top of the food chain. A Murray cod will eat almost anything smaller than itself. Its meals include other fish, wriggly yabbies, freshwater shrimp, and Murray crayfish. Every now and then a hungry cod will even snap up a duck, a turtle, or a water snake that comes too close.

The Murray cod is named after the Murray River, and its true home is the Murray-Darling basin, Australia’s largest river system. This huge web of rivers drains a big slice of the continent, so the cod can be found in many kinds of water, from cool, clear mountain streams to wide, slow, muddy lowland rivers.

Murray cod are patient hunters. During the day they often wait quietly near sunken logs and hollows, then at night they become bold, roaming swimmers, searching the river for their next meal. They are also very long-lived fish, so a single cod can watch over its stretch of river for many, many years.

People in Australia care deeply about the Murray cod. Sadly, too much fishing long ago meant that huge old cod became rare, and changes to the rivers have made life harder for them. Today they are protected by law in Australia, and people work to keep the rivers healthy — leaving snags and cool, clean water — so these gentle river giants can keep gliding through the Murray-Darling for a long time to come.