Moorish idol

Photo: louisseattle · © all rights reserved

Moorish idols are one of the most recognisable reef fish in the Pacific, with their dramatic black, white, and yellow banding and elongated dorsal filament, and they are reliably encountered at Second Cathedral in pairs and small groups foraging on sponges encrusting the chamber walls. Despite their abundance at Hawaiian dive sites, they are notoriously difficult to keep in captivity — the species gained pop-culture recognition as the character Gill in Finding Nemo. Their feeding on sponges and tunicates plays an important grazing function on Hawaiian reef walls, comparable to the role surgeonfish play on shallow coral flats.