Latin name

Alepes melanoptera

Other names

Shortfinned trevally, chinese trevally

Identification

Have a body profile very similar to that of Alepes apercna, but is easily distinguished by the pronounced black coloration of the dorsal fin. This species tends to become more elongated with age, resulting in a slight change in body proportions. It has an elongated, compressed body with dorsal and ventral profiles that are almost equally convex in shape. The nose is slightly more blunt than in other members of the genus, and the mouth is full of numerous comb-like teeth. The blackfin scad has a fatty eyelid that is only well developed in the posterior part of the eye. The lateral line is strongly curved anteriorly, with the curved and straight portions of the line intersecting just after the beginning of the spiny dorsal fin. The curved portion of the lateral line contains 31 to 50 scales and up to 2 flaps, while the straight portion contains up to 4 scales and 49 to 69 flaps. The number of gill stamens ranges from 24 to 30, and this species has 24 vertebrae. 

Features of fish fins

The dorsal fin is divided into two parts as in all carangids, the first having 7 or 8 spines and the second having a single spike followed by 23 to 26 soft rays. The anal fin consists of two separate spines followed by a single spike and 18 to 21 soft rays. Both the anal and dorsal fins have a low profile. The pectoral fin is sickle-shaped and extends beyond the junction of the curved and straight portions of the lateral line. 

Fish colouring

The upper body of the fish is silver blue on top, silver white underneath with a scattered black spot. The webbing of the first, spinous dorsal fin is black, giving the species its common name. All other fins are pale to hyaline, except the caudal fin, which is dark yellow with darker edges.

Distribution

Widespread throughout the tropical and subtropical Indo-Pacific region. This species has been recorded as far west as the Persian Gulf (Kuwait), has a rare distribution in the western Indian Ocean as far west as India and Sri Lanka. It is common along the Asian coast, in Malaysia, Thailand, the Philippines and as far south as Indonesia. The northernmost catches have been made in Okinawa, Japan, and one specimen has been collected off the coast of Taiwan. 

Habitat

Marine; brackish; pelagic; tropical species. Adults inhabit coastal waters, not found in the open ocean.

Size

The maximum known length is 25 cm.

Behavior

They lead a gregarious lifestyle.

Food and feeding habits

This species is a planktivorous predator that feeds on a variety of pelagic shrimp, crustaceans and paddlefish.

Reproduction

Spawning occurs in the warm season. The fecundity of the fish is quite high, as the eggs remain suspended in the water column after spawning. The hatched larvae feed on small plankton.

Fishing

It is mainly caught by hook and line and is not considered a major commercial species in any region. However, it is highly prized in Cambodia and Thailand.

Relationship with a person

A species harmless to humans.