Indian Sailfin Tang

Zebrasoma desjardinii is a marine reef tang in the fish family Acanthuridae.

Description

Zebrasoma desjardinii grows to a maximum length of 40 cm (16 in), with a sexual dimorphism, as males being larger than females. This species shows the typical morphology of the family Acanthuridae. The body is oval or disc-shaped, with erectile and much elevated dorsal and anal fins. The coloration may vary from one individual to another and within the same individual, depending on age. In general, the upper side of the body alternates orange and dark blue vertical bands, with a larger blue band on the eyes, a spotted ventral region and numerous white spots on the head. The dorsal and anal fins have a pattern of horizontal alternate orange and blue bands. The caudal fin shows white spots and lines.

Like most surgeonfish on each side of the caudal fin, in the middle of the caudal peduncle, there is a defensive dark spine surrounded by a blue zone. This spine is hinged and may unfolds to 80°.

In respect of Zebrasoma veliferum, adult Red Sea Sailfin tang has a few less anal fin rays (22-24 instead of 23-26) and different marking on the tail. As a juvenile, they are almost indistinguishable in color and markings.

Behavior

Adults usually can be found in pairs, while juveniles are solitary. When threatened, these fishes display their large ventral and dorsal fins. They feed primarily on filamentous algae, various macroalgae and plankton. However, individuals were regularly observed feeding on jellyfish (Scyphozoa) and comb jellies (Ctenophora) in the Red Sea. They are pair spawners, a typical trait of other fish in the Zebrasoma genus. This differs from the group spawning typical of the Acanthuridae family.

Distribution

This species is widespread in the Indian Ocean from the southern Red Sea to KwaZulu-Natal Province in South Africa and as far east as India and Java.

Habitat

Red Sea sailfin tangs natively live in lagoons and reefs in a tropical climate. The juvenile fishes live in the inner reef areas. They prefer saltwater with a specific gravity of 1.020 - 1.025, a pH between 8.1 and 8.4 and an ideal temperature range of 22 - 26 C (72 - 78 F). They may live at water depths of 2 – 30 m (6.5 – 100 ft) or more.