Kingdom: Animalia

Phylum: Chordata

Class: Actinopterygii

Order: Perciformes

Family: Zanclidae

Genus: Zanclus

Species: Z. cornutus

Physical Description

Moorish idol has a compressed discoid body and reach a maximum length of 23 cm. It have a tubular snout with a small mouth containing numerous elongate bristle-like teeth. Dorsal spines elongated into a whip-like filament. Moorish idols stand out in contrasting bands of black, white, and yellow, which makes them attractive to aquarium keepers. The fish have relatively small fins, except for the dorsal fin, whose six or seven spines are dramatically elongated to form a trailing, sickle shaped crest called the philomantis extension.

Biology and Behavior

These are Benthopelagic fishes that are generally encountered in small groups of 2 or 3 individuals. Adults occur singly, in pairs and occasionally are seen in large schools. Feed on small encrusting animals. Size of metamorphosis from post larva to juvenile is 7.5 cm. The long pelagic larval stage is the reason for the wide distribution and strong colouration that shows no geographical variation. Popular aquarium fish but rarely survives in tanks.

Habitat and Distribution

Inhabit turbid inner lagoons, reef flats, and clear seaward rocky and coral reefs of  Indo-Pacific: East Africa to Rapa and Ducie islands, north to southern Japan and the Hawaiian Islands, south to the Lord Howe Island. Eastern Pacific: southern Gulf of California to Peru

Reference:

http://www.fishbase.org/summary/5950

https://www.thespruce.com/moorish-idol-2925721