Powderblue Surgeonfish

A colourful tropical marine fish, with the scientific name Acanthurus leucosternon. It is mainly greyish-blue, with for the most part a yellow dorsal fin, a black face with a rather large eye, a white mouth and chin (or upper breast), and white ventral and anal fins, while the pectoral fins are transparent with a yellow reflection, and the tail white and black. The name surgeonfish derives from two hard spines at the base of its tail, one spine on each side of the body, that lie flat in a groove and which are as sharp as a surgeon's scalpel. When the fish is provoked or feels threatened, these spines can be used as a defensive weapon, as when the fish flips its tail, the spines pop out like small scalpel-like knives. This fish lives solitary or in small groups and dwells most of its time in shallow waters. It is herbivorous, feeding mainly on algae that grows on rocks, and as such is commonly found in shallow rocky shores, or exposed coral reefs. It is also called Powderblue Tang and in Thai it is known as pla khih tang bet fah ok khao (ปลาขี้ตังเบ็ดฟ้าอกขาว), which translates as ‘white-breasted blue hook tang fish’. Also spelled Powder Blue Surgeonfish. See also POSTAGE STAMPS. 回