Tarwhine are very similar to bream species, however they have a more rounded head profile, and bream lack the golden stripe colouration and have a greater number of scale rows above the lateral line. Tarwhine generally have a silvery body with rows of close-set yellow spots forming longitudinal stripes. The dorsal and caudal (tail) fins are yellowish close to the body with a dark margin. The pelvic and anal fins are a bright yellow, which tend to fade as the fish matures, with the pectoral fins being a clear dusty yellow. Tarwhine grow to a maximum length of 45 centimetres.
Tarwhine are widespread throughout the Indo-pacific. In Australia they range from Coral Bay to Albany, WA and Lake Entrance, Victoria to southern Queensland. Tarwhine have been shown to undergo size-related movements, starting off by settling in sheltered, sandy surf shorelines. From there they move progressively to nearby seagrass beds and then to exposed sandy surf shorelines and finally they move out to areas around inshore reefs to depths of 35 metres where ocean spawning occurs from July to November. Small benthic invertebrates such as crustaceans and molluscs comprise most of a tarwhine’s diet, but as they get older they change their diet to become herbivorous. Tarwhine tend to form small schools along the coast and occasionally mix with bream.
Occurrence at the Busselton Jetty:
Tarwhine are relatively common in the waters of Geographe Bay. Small aggregations are often observed passing through the open water zone down to the seafloor, and are often seen to pause and feed along the benthos stirring up the sediment in search of invertebrate prey.
Image by: O. Rynvis