Moorish idols

The Moorish idol is a single, unmistakable reef fish known for its long, trailing dorsal fin. In this app the group includes just the Moorish idol.

The white body, two black bands, yellow markings, and long trailing dorsal filament make this fish easy to tell apart from any other reef fish at a glance. Small bony bumps above the eyes appear as the fish matures.

The body is flat from side to side and shaped like a disc, with a small mouth on a tube-like snout. The dorsal fin has a long, whip-like filament trailing from it. The body is white with two wide black bands, a yellow patch near the tail, and a yellow saddle on the snout. Adults grow to about 21 cm.

Moorish idols live on reefs across the Indian and Pacific Oceans, from East Africa to Hawaii, and in the eastern Pacific from Mexico to Peru. They live in lagoons, reef flats, and both murky and clear rocky or coral reefs, from just below the surface down to 180 metres.

Moorish idols are usually seen alone, in small groups of two or three, or sometimes in large schools.

Moorish idols mostly eat sponges, which make up most of what they eat by weight. They also eat algae, coral polyps, tunicates, and other small animals living on the reef.

Moorish idols release eggs and sperm into the open water, where fertilised eggs drift away on the current. The young spend a long time drifting in open water before settling on a reef, which helps spread the species over a wide area.

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  Moorish Idol

  Zanclus cornutus