Scarus spinus

Scarus spinus, the Greensnout parrotfish, is a species of marine ray-finned fish, a parrotfish from the family Scaridae.

Description
Scarus spinus can reach a total length of about 30 cm (in males). These fishes have 10 dorsal soft rays, 3 anal spines and 9 anal soft rays. Males show a bright yellow head underwater, while females are drab with white teeth and some pale spots. Caudal fin is moderately to deeply emarginate in terminal phase. Lips largely cover dental plates.

Distribution and habitat
This species can be found on Christmas Island and from the Philippines  to Samoa, the Ryukyu Islands  and the southern Great Barrier Reef. The Greensnout parrotfish inhabits coral-rich areas of outer lagoon and seaward reefs, at a depth range 0 - 30 m.

Biology
It appears specialized in scraping crustose coralline algae with its jaw. It can change gender from female to male (hermaphroditic).