ACANTHURIDAE Surgeon fishes
Elongate and deep compressed body shape; thick-skinned with small roughish scales. Small mouth with incisor-like teeth for grinding, used to remove tiny invertebrates and algae from rocks. Colourful residents of the inshore reefs surgeon fishes are so-called because of their ability to slash at other fish aggressively with their sharp, scalpel-like spines forward of the caudal fin, by a side-swiping movement of their tail.
Sohal favour the surf zone adjacent to shallow rocky outcrops interspered with coral, and are often observed grazing in large schools. Most surgeon fishes graze on bottom-dwelling algae and some also feed on zooplankton. Acanthurus sohal ; Zebrasoma xanthurus .
Surgeon fish or sohal Acanthurus sohal
Distinctive and colourful with high forehead and lunate caudal fin with blue margins. Dark blue dorsally with dark horizontal stripes over silvery sides, yellow sub-laterally. Pectorals yellow with dark edges. Matching long dorsal and ventral fins also have electric blue edges. Bright orange spine on caudal peduncle.
Arabian Gulf and east coast coral reefs, and inshore rocks and islands.
One of the commonest coral reef fishes, and easily observed inshore in the inter-tidal surf zone on shallow reefs, where they work the marginal rocks, scraping algae with their sharp teeth. They can be inquisitive and aggressively defend their home range. Often caught in nets and traps and discarded by fishermen as unmarketable. 30-75 cm
Yellowtail surgeonfish Zebrasoma xanthurum
Deep-bodied, high forehead; dark blue-black body with caudal fin bright canary yellow. Dark horizontal stripes which break into spots on shoulder and head. Another colourful resident of the inshore reefs which can often be seen while snorkelling. 22 cm