Longfin Trevally

The Longfin Trevally is a lesser-known member of the jack family (Carangidae) found in coastal waters of the Indo-West Pacific, from the Red Sea and East Africa to Southeast Asia and northern Australia. It belongs to the genus Carangoides, a diverse group of moderately deep-bodied trevallies distinguished by details of fin shape and scute arrangement. As its name suggests, it is characterized by elongated soft dorsal and anal fin lobes, particularly noticeable in younger individuals. It typically inhabits sandy and reef-adjacent coastal habitats and, while not a major target of commercial fisheries, remains a regularly encountered species across its broad Indo-Pacific range with no notable conservation concerns.

• Moderately deep, laterally compressed, oval body
• Silvery body with a faint golden or greenish sheen on the back
• Elongated, filamentous tips on the soft dorsal and anal fins, especially in juveniles
• Small black spot on the upper gill cover in some individuals
• Blunt, rounded snout
• Forked tail with dusky margins

Typically 30-45 cm, up to 65 cm. The extended fin filaments and moderate body depth help distinguish it from more deep-bodied Carangoides relatives and from the smoother-finned Caranx jacks.

Longfin Trevally occur in coastal and inshore waters throughout the Indo-West Pacific, from the Red Sea and East African coast eastward through the Indian Ocean to Southeast Asia and northern Australia. They favor sandy bottoms, silty coastal areas, and habitats adjacent to reefs, typically at depths from a few meters down to around 60 m. They are more often associated with turbid, soft-bottom coastal environments than clear offshore reefs, distinguishing their habitat preference from many other trevally species. Juveniles may occur in shallower nearshore waters and estuarine margins before adults move into slightly deeper coastal habitat.

Longfin Trevally are generally found alone or in small, loose groups rather than the large dense schools typical of some Caranx species, often foraging near the seafloor over sand and silt bottoms. They feed primarily on small benthic invertebrates and fish, using their coastal, soft-bottom habitat to locate buried or hidden prey. Spawning behavior is not well documented but is presumed to follow the broadcast-spawning pattern typical of carangids, with pelagic eggs and larvae. As a coastal predator over sandy and reef-fringe habitats, it contributes to the broader diversity of mid-sized predatory fish along Indo-Pacific coastlines.