Golden trevally

The golden trevally (Gnathanodon speciosus), also known as the golden kingfish, banded trevally or king trevally, is a species of large marine fish classified in the jack and horse mackerel family Carangidae, and the only member of the monospecific genus Gnathanodon. The golden trevally is widely distributed throughout the tropical and subtropical waters of the Indian and Pacific Oceans, ranging from South Africa in the west to Central America in the east, extending to Japan in the north and Australia in the south. The species predominantly occupies inshore waters where it inhabits both reef and sandy substrates. The golden trevally is easily distinguished from its relatives by its fleshy, rubbery lips and unique colouration, which ranges from bright yellow with black bars as a juvenile to a golden-silvery colour as an adult. It is known to grow to 120 centimetres (47 in) in length and 15 kilograms (33 lb) in weight. The golden trevally schools as a juvenile, often closely following larger objects including sharks and jellyfish. The species uses its protractile jaws to suck out prey from the sand or reef, and consumes a variety of fish, crustaceans and molluscs. Spawning aggregations gather at night at different times of the year throughout its range. The golden trevally is a considerable constituent of several Middle Eastern fisheries and being of minor importance to many others, with a worldwide annual catch of 1,187 metric tons (1,168 long tons; 1,308 short tons) to 3,475 metric tons (3,420 long tons; 3,831 short tons) recorded between 2000 and 2010. The golden trevally is a popular gamefish, taken by bait, lure, fly and also spear throughout its range. Several Asian countries currently farm the fish in caged aquaculture. Due to their brilliant colouration, juveniles are popular in marine aquaria.

Distribution

The golden trevally is widely distributed throughout the tropical and subtropical waters of the Indian and Pacific Oceans. In the Indian Ocean, the species is distributed from South Africa along the east African coastline, including the Red Sea and Persian Gulf. Its distribution extends east along the Indian and South East Asian coastlines, and south through Indonesia and northern Australia. Golden trevally are recorded from many Indian Ocean islands including Madagascar, Seychelles and The Maldives. In the Pacific, the species is spread throughout the South East Asian and Indonesian archipelago north mainland China and Japan and south to eastern Australia and New Zealand. Golden trevally have been recorded from many central Pacific Islands, including Hawaii, with their distribution extending to Central America. Here its range extends from the Gulf of California in the north to Colombia in the south.

The golden trevally predominantly occupies inshore waters of varying substrate, although is known to occur on deeper continental shelf reefs in Australia. In coastal areas the species inhabits rocky and coral reefs as well as open sand flats where it forages for food. A systematic study in northern Australia indicated it to be one of the only species to be approximately equally distributed in both reef and soft-bottom habitats. Golden trevally appear to prefer clear water to turbid waters, and thus is only encountered rarely in low turbidity estuarine environments. One known exception to this was the capture of several individuals in a shallow mangrove swamp in Baja California which appeared to be foraging for prey.