Western Australian salmon

Arripis truttacea, the Western Australian salmon, is a species of marine ray-finned fish within the genus Arripis, the only genus within the family Arripidae. It is endemic to the seas off southern Australia.

Habitat

Arripis truttacea adults gather in large schools along exposed beaches and rocky reefs while the juveniles use shallow bays and estuaries for nursery areas, the juvenils are frequently recorded in beds of Posidonia sea grass and in creeks lined with mangroves of the genus Avicennia. The schools of adults may also be found in estuaries and in deeper offshore waters. This is a carnivorous species which preys largely on small pelagic, schooling fish, known as baitfish. In turn, it is preyed on by seals, dolphins and sharks.

The Western Australian salmon arrive off south western Australia from March onwards to spawn, mainly congregating in the waters between lying between Cape Leeuwin and Busselton in late autumn and early winter. Their arrival coincides with the peak of the strength of the eastward flowing Leeuwin Current and associated easterly winds. These then carry the newly hatched larval fish southeastwards. The larvae settle all along the southern coast of Australia but the majority are transported to the waters off Victoria and Tasmania. They mature in the nursery grounds which are situated between South Australia and Tasmania for a period of three to four years before migrating west to Western Australia, occurring in schools in the vicinity of Hopetoun and Esperance. Once the run of spawning is over, in mid-winter, the adults move back to the south-eastern Western Australian waters.

Distribution

Arripis truttacea is endemic to the coastal waters of southern Australia where it is found from Lakes Entrance in Victoria to Kalbarri in Western Australia, although it is rare north of Lancelin in Western Australia.