The species is common in tropical to subtropical waters of the Indo-Pacific, ranging from South Africa in the west to Japan in the east, typically inhabiting inshore reefs and bays.

Longfin trevally are pelagic predators, taking a variety of small fish, cephalopods and crustaceans, and reach sexual maturity at around 21 cm.

The longfin trevally has a very complex taxonomic history which is closely intertwined with another currently valid species, Carangoides ciliarius, which may yet prove to be synonymous.

Longfin trevally are of minor importance to fisheries throughout their range and are considered good table fish, and are occasionally taken by anglers.

Finally, the species was placed in Carangoides after re-examinations of its anatomy by a number of authors as part of a larger investigation into the taxonomy of the carangid fishes.

Sciaena armata, originally named by Peter Forsskål in 1775, has never been definitively identified,[6] but in the same volume he described C. armatus in, Rüppell created Citula ciliaria.

[11] The second dorsal fin is sexually dimorphic, with mature males longer than 21 cm having 3 to 12 of the central soft rays extended into thin filaments of varying lengths.

Younger individuals show a more silver blue dorsally, and have six dark crossbars visible on the body past the pectoral fin base.

[10] Longfin trevally are generally too rare to be a viable target for commercial fisheries, although they are occasionally landed and sold fresh locally.

[13] Small quantities are taken by recreational fishermen in South Africa, often from boats using fish baits on hook and line gear or lures, as well as by spear.