Zanclus cornutus, S
With a highly compressed disc or oval-shaped body, Moorish Idols have contrasting vertical bands of black, white and yellow. A small mouth is located at the end of a long, tubular snout, with an orange saddle across the snout. Adults have small bony projections, 'horns', above their high-set eyes and these are larger in males. Moorish Idols have relatively small fins, except for their long sickle-like crest which trails from the dorsal fin. The dorsal fin comprises 7 spines, of which the third extends to form a long, sickle-like filament, which shortens with age. Longer, trailing dorsal fins indicate younger fish. The long dorsal fin is likely to deter predators, which include Moray Eels. Adults commonly reach 15 – 16 cm in length and are thought to have a lifespan of 4+ years. Similarly to Butterflyfish, Moorish Idols mate for life and can be seen singularly, in small groups or 2 - 3, sometimes in small schools of 10 – 20, and occasionally in larger schools of 100 – 200+ around some of our dive sites.