Yellowtail Tang

Zebrasoma xanthurum, commonly known as the purple tang or yellowtail tang, is a marine ray-finned fish species within the family Acanthuridae, which also includes surgeonfishes, unicornfishes, and tangs. This species is exclusively found in the northwestern 🌊 Indian Ocean.

The specific name "xanthurum" is derived from Greek, meaning "yellow tail," in reference to the species' distinctive yellow caudal fin.

Zebrasoma xanthurum is characterized by a dorsal fin supported by five spines and 24 or 25 soft rays, while the anal fin features three spines and 19 or 20 soft rays. This species possesses a deeply laterally compressed body, a protruding snout, and prominent dorsal and anal fins. The body's depth is proportioned to fit 1.7 to 1.9 times into its standard length, and the longest dorsal fin ray measures 3.3 to 3.7 times into the standard length. Its snout exhibits a concave profile on both sides. A velvet-like patch of bristles is located on the caudal peduncle anterior to the spine. Juvenile specimens display a rounded caudal fin, which may develop a slightly rounded or truncate shape in adults. The adult head and body are predominantly dark blue to purple, contrasted by a vibrant yellow caudal fin. Black spots adorn the head and anterior body, extending to adjacent fins, while the body and fins feature irregular black horizontal lines, excluding the caudal fin. The pectoral fins have a yellow outer third, and younger fish exhibit dark brown longitudinal lines across their bodies. The maximum published total length for a yellowtail tang is 36.7 cm (14.4 in), though more commonly, they measure around 10 cm (3.9 in).

Zebrasoma xanthurum's habitat is restricted to the northwestern 🌊 Indian Ocean, prominently within the 🌊 Red Sea, the 🌊 Gulf of Aden, and along the Arabian Peninsula coastlines, extending into the 🌊 Persian Gulf. The species is also present around Socotra (🇾🇪 Yemen). A recorded sighting from Sardinia in 2015 was likely an aquarium release, while a record from the 🇲🇻 Maldives is presumed a misidentification, and the type locality of 🇱🇰 Sri Lanka is considered erroneous. These fish typically inhabit groups at depths reaching 20 meters (66 feet) in coral-rich or rocky environments.

Primarily herbivorous, Zebrasoma xanthurum grazes on filamentous algae. During the day, they forage either individually or in pairs, ceasing at sunset when they retreat to shelters among corals or in crevices for the night. Juvenile purple tangs are cryptic, hiding among corals.