Latin name

Alepes vari

Other names

Duskyfin crevalle, trevally scad.

Identification

Have a body profile very similar to other members of the genus Alepes, with a highly compressed ovoid body. The ventral and dorsal profiles of the fish are almost uniformly convex and are joined anteriorly by a pointed snout. The lateral line is strongly curved anteriorly, and the junction of the curved and straight sections is located from the beginning of the second dorsal to the third soft ray. The curved portion contains 42 to 50 scales and 0 to 2 shields, while the straight portion contains 0 to 7 scales and 48 to 69 shields. The posterior half of the eye has a well-developed fatty eyelid. The jaws contain a single row of numerous comb-like teeth. They have 32 to 38 gill blades and a total of 24 vertebrae. 

Features of fish fins

Herring Scad have two separate dorsal fins, the first containing 8 spines and the second containing a single spike followed by 24 to 27 soft rays. The anal fin consists of two small spines in front of each other, followed by a single spine connected to 20 to 23 soft rays. 

Fish colouring

The coloration of the fins is ashy blue on top, turning silvery white underneath, with a scattered dark spot along the edge of the cap. The fins are dark except for the spiny dorsal fin, which is light to dark brown. The amount of dark pigment in the fins is sexually dimorphic: in males, the spinous dorsal fin, the lobes of the soft dorsal and anal fins, and the pelvic fins are darker than in females.

Distribution

Widespread in tropical and subtropical regions of the Indo-West Pacific. This species has been recorded from the Red Sea eastward to Sri Lanka, India, Southeast Asia, China, Indonesia, the Philippines, New Guinea, northward to Taiwan, and southward to northern Australia. 

Habitat

Marine; pelagic-neritic; a tropical species that prefers brackish waters. Depth range 0-10 m. Most commonly found in shallow coastal areas where fish live in the surface ocean on a variety of substrates.

Size

This species is by far the largest of the Alepes species, reaching a total length of 56 cm, although they are more commonly found under 30 cm.

Behavior

Adults are common in shallow coastal waters where they often swim near the surface. They form dense schools on transparent inner reefs, swimming high above the surface. 

Food and feeding habits

A carnivorous species that feeds on a variety of crustaceans, including shrimp, paddlefish and ten-legged clams, as well as other small fish. It is one of the many pelagic fishes of the Red Sea whose intestines have been found to contain large numbers of luminescent bacteria that live in symbiosis with the fish as part of the intestinal flora.

Reproduction

Egg laying species, females lay eggs. During the breeding season, females release large numbers of eggs into the water for males to fertilize with their sperm. A small female may lay a few hundred thousand eggs, while a larger female may lay several million eggs during a single spawning season. The eggs float freely in the water until they hatch into fish larvae only a few millimeters long. The average incubation period is just over a week.

Fishing

This species is not important to fisheries and is occasionally caught on hook and line. Sometimes used as bait or bycatch.

Relationship with a person

The flesh of these fish is of good quality and in some regions is considered a premium product, sold fresh, dried and salted.