Distinguished from other trevally species by its striking colouration, the golden trevally (Gnathanodon speciosus) is beautiful bright yellow or golden as a juvenile and young adult, with a narrow black bar through the eye and between 7 and 12 vertical black bars, of alternating widths, along the body. The fins of this small fish are yellow, while the tail (caudal fin) is black-tipped and deeply forked. The second dorsal fin is larger than the first, and the pectoral fins are long and sickle-shaped (3). As the golden trevally grows, the yellow becomes more silvery and iridescent, the black bars fade, and scattered, blackish blotches develop on the sides of the body (3)(4)(5)(6)(7). The golden trevally has thick, fleshy lips and a protractile (extendable) mouth. Adults lack teeth, and only a few small teeth are present in the lower jaw of juveniles (4)(7)(8)(9).
Also known as
gold-barred jack, golden horsmackerel, golden jack, golden king, golden kingfish.
The golden trevally is a fast-swimming, predatory fish. It typically hunts in small groups, foraging in the sand for invertebrates (usually molluscs and crustaceans) and small fish, which are sucked up into the mouth by extending the protractile jaws into a tube (3)(4)(5)(6). Juvenile golden trevally often mimic the behaviour of pilot fish (Naucrates ductor), associating closely with sharks and other large fish (3)(4)(5)(7), and are also known to live among the tentacles of jellyfish (possibly for protection against predators) (2)(6).
Spawning occurs during April and May, with studies on the biology of the golden trevally showing that growth of the population occurs fastest during the summer months (2).
The golden trevally is not currently considered threatened; however, it is exploited for small scale commercial or subsistence fisheries in coastal waters, usually using artisanal fishing methods such as gillnets and spears. Juvenile golden trevally may be taken for the aquarium trade (2).
Diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.
The unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans.
Animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones), echinoderms, and others.
A diverse group of invertebrates, mainly marine, that have one or all of the following; a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.
In fish, the pair of fins that are found one on each side of the body just behind the gills. They are generally used for balancing and braking.
The production or depositing of large quantities of eggs in water.
Grandcourt, E.M., Al Abdessalaam, T.Z., Francis, F. and Al Shamsi, A. (2004) Population biology and assessment of representatives of the family Carangidae Carangoides bajad and Gnathanodon speciosus (Forssk°al, 1775), in the Southern Arabian Gulf. Fisheries Research, 69: 331–341
Van der Elst, R. (1993) A Guide to the Common Sea Fishes of Southern Africa. Struik Publishers, Cape Town, South Africa.
Randall, J.E. (1995) Coastal Fishes of Oman. Crawford House Publishing Pty Ltd, Bathurst, Australia.
King, D. and Fraser, V. (2001) More Reef Fishes and Nudibranchs: East and South Coast of Southern Africa. Struik Publishers, Cape Town, South Africa.
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