Sailfin Tang

The Sailfin Tang is a large, dramatically finned surgeonfish (family Acanthuridae) in the genus Zebrasoma, native to the Indo-Pacific. Its greatly enlarged dorsal and anal fins, which can nearly double its apparent body height, give it a sail-like silhouette that inspired its common name. It is one of the most recognizable tangs on Indo-Pacific reefs and a long-standing favorite in the marine aquarium trade. Wild populations remain widespread and are not currently at risk, and the species is an important algae grazer on reef habitats throughout its range.

• Very deep, laterally compressed, disc-like body
• Base color cream to brown with numerous thin dark vertical stripes and pale spots
• Extremely tall dorsal and anal fins forming a sail-like profile, edged in yellow
• Small, tapering snout adapted for browsing
• Sharp scalpel spine at the base of the tail
• Juveniles are more vividly striped than duller adults; reaches 30-40 cm

Distinguished from the similar Purple Tang and Desjardin's Sailfin Tang by its striped (not solid) coloration and taller sail fins.

Sailfin Tangs are found on coral reefs and rocky reef flats throughout the tropical Indo-Pacific, from the East Indies and Micronesia to the western Pacific islands. They occupy depths from the shallows down to about 30 m, favoring clear, warm water with abundant algae-covered rock and coral rubble. Juveniles often shelter in shallow reef crevices and tide pools, while adults range more openly over reef slopes and lagoon patch reefs, using their laterally flattened shape to slip between coral branches.

This species spends much of the day grazing algae from rock and coral surfaces with its small, brush-like teeth, playing a significant role in limiting algal growth on reefs. Sailfin Tangs are usually solitary or seen in loose pairs, though juveniles may aggregate in small groups in sheltered reef nurseries. They erect their tall dorsal and anal fins and flare their sharp caudal spine when threatened or contesting territory with rivals, using the spine as a defensive weapon in lateral tail-slashing displays. Spawning takes place in open water during dusk aggregations.