East African coast to the Red Sea and across to India and Southeast Asia. The species ranges south to Australia and Indonesia, and as far as Japan, Hawaii, and a number of Pacific islands, including Micronesia, New Caledonia, and Tonga. The blue trevally inhabits coastal waters to a depth of 60 m, over reefs, beaches, lagoons, and areas with sandy substrates. The species lives pelagically, allowing movement between islands and atolls. It is rarely found in estuaries, suggesting a poor tolerance to low salinities. Biology and fishery Like many Indo-Pacific carangids, the biology and ecology of the blue trevally is poorly known, with the only data on the species relating to its diet. It is a fast-swimming predator which often forms small schools, and takes a variety of small fish (specifically mackerel and filefish), crustaceans including prawns, crabs, and sea lice, soft molluscs, and other soft prey. In Hawaii, they have been observed following foraging bonefish or goatfish, consuming any scraps uncovered by the foragers. The species appears to be in constant abundance all year, but ripe individuals have rarely been reported. No information regarding the reproduction and growth of the species is available, although larvae of the species are known to appear during February in the waters off Taiwan, suggesting a December spawning period, and make up a high proportion of the larval abundance. Juveniles are known to sometimes shelter among the tentacles of large pelagic jellyfish. The species is of commercial importance in a number of areas due to its high abundance, or more often taken as bycatch in other major fisheries. Catch statistics for the individual species are rarely kept, though, and it is generally grouped with other trevallies. It is caught mainly on hook and line and with gill nets and various traps. In South Africa, it is considered a popular gamefish, and is often taken by anglers using various small baits, with the best catches had at dawn and dusk. It is considered to be an excellent table fish, although ciguatera poisoning attributed to this fish has been reported rarely. References External links Information page at Australian Museum Online Description at Hawaiian fishes.com Blue trevally at Fishbase blue trevally Marine fauna of East Africa Marine fish of Northern Australia Fish of Micronesia blue trevally