Blue Trevally - Biology and Fishery

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. The blue trevally 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 appear 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 it is known that larvae of the species 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, as well as 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 there have been rare reports of ciguatera poisoning attributed to this fish.