Barramundi

The barramundi is a big, silvery fish with large, shiny scales and a wide mouth. People also call it the Asian sea bass. It lives across the warm Indo-Pacific, from the Middle East all the way to the rivers and coasts of Southeast Asia and northern Australia. With its long, strong body, the barramundi is a graceful swimmer in both rivers and the sea.

One of the most interesting things about barramundi is that they are travellers between two kinds of water. They spend much of their lives in freshwater rivers, but when it is time to breed they swim down to the river mouths and estuaries where the water turns salty. Being comfortable in both fresh and salty water is a special skill that not many fish share.

Barramundi also have a remarkable life story. Most of them begin life as males, and then, as they grow older, they slowly change into females — usually somewhere between about three and eight years of age. So a single barramundi may live part of its life as a father and later become a mother.

These fish are carnivores, which means they eat other animals. Grown-up barramundi hunt smaller fish, along with crustaceans like prawns and crabs, and shelled creatures called molluscs. When they are young, they start out by eating tiny drifting animals called zooplankton before moving on to bigger meals as they grow.

Barramundi can grow surprisingly large — up to around 1.8 metres long — although most that people meet are a good deal smaller. They are listed as Least Concern globally, but that does not mean every local population is equally healthy. Looking after connected rivers, wetlands, mangroves, and estuaries helps these fish keep moving between the fresh water and the sea they both call home.