
Bicolour parrotfish
Cetoscarus bicolor
Scarus prasiognathos

The Singapore parrotfish is one of the giants of its family, reaching 70 cm. It grazes the reefs of the eastern Indian Ocean and western Pacific, mostly on outer slopes, but it will come into shallow water where the coast is sheltered. Like other parrotfish it changes as it grows, and the big males end up looking quite unlike the fish they started as.
Also known as: dusky parrotfish, green-face parrotfish, greenthroat parrotfish, ocean parrotfish, singapore parrotfish, ocean parrotfish, dusky parrotfish, green-throat parrotfish, greencheek parrotfish, parrotfish, greenthroat parrotfish, green-face parrotfish, singapore parrotfish, green-throat parrotfish, greencheek parrotfish
Early-phase fish are easy to confuse with other parrotfish and often cannot be told apart in the water. Large males are the ones to name. Look underneath the head as the fish turns: the throat is a vivid green, brighter than anything else on the body, and no other parrotfish on these reefs shows it. Check the back fin too, since the lack of a trailing thread rules out look-alikes that carry one.
A heavy-bodied parrotfish with the fused, beak-like tooth plates of the family. The lips almost cover those plates, so little of the beak shows. The tail changes with age and sex: in early-phase fish the rear edge is only slightly notched, while in large terminal males it is deeply forked. The middle spine of the back fin stays short, with no long thread trailing from it.
Describe what you saw and we name it, then keep every species you find in your Oceandex.