Yellowfin bream, Sea bream, Surf bream, Silver bream, Eastern black bream
Acanthopagrus australis, the yellowfin bream, also known as sea bream, surf bream, silver bream or eastern black bream, is a species of marine and freshwater fish of the porgy family, Sparidae. It is a deep-bodied fish, occasionally confused with Acanthopagrus butcheri (black bream), but is generally distinguished by its yellowish ventral and anal fins. It is a popular target for recreational fishermen due to its capacity to fight well above its weight coupled with its table quality.
The yellowfin bream is a slower-growing species than the related black bream, reaching a fork length of 23 cm (9 in) in five years, having matured when 22 cm (8.7 in) long. The colour can be variable: fish caught in freshwater may be bronze- or brown-coloured, while those caught in estuarine or marine habitats are more silvery.
A specimen measuring 56 cm (22 in) long and weighing 7 pounds 3 ounces was caught in the Georges River and reported in 1928, while another even longer specimen from the Clarence River was 58.5 cm (23 in) and 7 pounds 2 ounces.
Yellowfin bream are found along the east coast of Australia from around 19 S to 38 S—roughly from Townsville in northern Queensland to Mallacoota and the Gippsland Lakes region in eastern Victoria. A yellowfin bream specimen was first identified in New Zealand waters in Piwhane / Spirits Bay in 1990, likely introduced by ship dispersal of juvenile fish. Due to the large amount of fishing around Northland and the lack of subsequent specimens, it is unlikely that a population established.
The bream inhabit estuaries in salt or brackish water up to the fresh water limit, and inshore rocky reef habitats near ocean beaches and rocky headlands.
Carnivorous, the yellowfin bream is demersal, preying on small fishes and invertebrates such as crabs, shellfish, polychaete worms and ascidians that dwell at the bottom of estuaries. They are fond of oysters, and can be found around oyster farms.
Surf bream come downstream to river mouths during spawning season, typically winter, where they spawn and the females lay planktonic eggs. These hatch after a few days, and the young remain in the estuaries. Like other species of sparid fish, the surf bream have a gonad termed the ovotestis that is made up of ovarian tissue dorsally and testicular tissue ventrally, separated by connective tissue. The species is protandrous – male fish become female after the spawning season. The eggs hatch after 2.5 days, after which they spend approximately four weeks as pelagic larvae. Larvae and juvenile fish live exclusively in seagrass beds in shallow estuaries.
