Mulloway are predators with long streamlined body and a curved tail, making them powerful swimmers. When viewed at an angle, especially underwater, a row of brilliant silver spots or ‘portholes’ can be seen along the lateral line.

Mulloway have a good sense of smell and not very good sight, making them well equipped to feed at night and in dirty water. Mulloway like to eat lots of different types of food. Their favourite would have to be crustaceans. A swarm of crustaceans that we call mysid shrimp are a mulloway’s preferred food. They will also eat large bait fish including mulies, mullet, whiting, tailor or beach worms, squid, octopus and sand crabs. The juvenile mulloway are cannibals, eating other mulloway.

Mulloway are among a big group of fish known as 'croakers' that make a characteristic grunting, or croaking sound. The drumming noise is produced from the vibration of their swim bladder.

Not a lot in known about how and when mulloway breed. It is believed they spawn in WA during December and January and that they mate behind the breakers of the surf zone or maybe near the mouth of estuaries. Mulloway are thought to be sexually mature when they are about 70 - 80cm and weigh around 4kg at which time they are approximately five years of age.

Mulloway use the Swan River and other estuaries as both nurseries for the young to grow in and as adult feeding grounds.

Scientific and other names
Mulloway (Argyrosomus hololepidotus) are also commonly named jewfish, silver jewfish, school jew, river kingfish and butterfish (in the eastern states). Juveniles are known as soapies.

What they look like
Mulloway are predators, with a large mouth and small but strong canine teeth. They have thick scales all over their body. They have long bodies and outward curved, spade-like tails that makes them a powerful swimmer. Though their body shape hints that they are a slow-moving species, marine scientists suggest that mulloway are quite capable of short bursts of speed to outswim their prey.

Mulloway are silver in colour with pinkish highlights on their head; flanks (sides) and dorsal (back) surface. The fins are grey/brown to translucent (clear) in colour.

Where they live
In Australia, mulloway are found from Rockhampton in Queensland, right around the southern half of Australia to at least Exmouth in Western Australia.

In Western Australia, juveniles less than one year old are usually found in inshore marine waters. Young adults, being one to six years, are found in both estuarine and marine waters. Adult fish, six years and older, are generally found in marine waters, though still common in and near estuaries.

Where mulloway live depends on the salinity of the water. The bigger fish prefer very saline water which is almost like sea water. When the winter rains make the water less salty the adult fish will move to the open ocean.

Mulloway also live in waters off Madagascar and South Africa.