Barred Yellowtail Scad

The yellowtail scad has a body profile quite similar to that of the other fish often called 'scad' from the genera Decapterus and Trachurus, having a moderately compressed, oval-shaped body. The dorsal and ventral profiles of the fish are nearly evenly convex, with the two lines intersecting at the pointed snout. There are two separate dorsal fins; the first consisting of eight moderately high spines and the second of a single spine followed by 22 to 25 soft rays. The anal fin consists of two anteriorly detached spines followed by a single spine attached to 18 to 21 soft rays. The terminal soft rays of both the anal and dorsal fins are nearly twice as long as the penultimate rays, forming distinctive finlet-like structures, although are still attached to the main fin structure by interradial membranes. The lateral line is slightly arched anteriorally, with the intersection of the curved and straight section occurring below the sixth to eighth dorsal soft ray. The curved section contains between 39 and 57 scales, while the straight section has no to 10 scales and 36 to 49 scutes. Another of the major distinguishing features of the species is an adipose eyelid which fully encloses the eye except for a small vertical slit over the pupil. This feature is only observable in individuals greater than 10 cm, as juveniles below this length are still developing the eyelid. …

The yellowtail scad is widely distributed in the tropical and subtropical regions of the Indo-Pacific region. In the Indian Ocean, the species is known from as far south as South Africa, distributed north along the east African coast including Madagascar, and further north to the Persian Gulf, Red Sea, India, Sri Lanka and Southeast Asia. In the Pacific, the species is most prevalent in Southeast Asia, Indonesia, Philippines, extending southward to northern Australia, north to Japan, where only three specimens have been recorded, and as far east as Hawaii. The species is predominantly coastal, schooling in inshore waters to a depth of 80 m, often in large embayments with mangroves or over coral reefs. Like a number of carangids, juvenile yellowtail scad are known to congregate around floating objects, including jellyfish medusae, as well as manmade structures. In Kaneohe Bay, jellyfish medusae disappeared from the bay, causing the fish to switch from natural objects to manmade ones, causing concern for recruitment of the species in the future.