Prionurus is a genus of marine ray-finned fishes belonging to the familyAcanthuridae, the surgeonfishes, unicornfishes and tangs, although some of the species in this genus are called sawtails or doctorfish. The species in this genus are found in the Pacific Ocean with one species, P. biafraensis, found in the Atlantic Ocean.
Prionurus species have oval, compressed bodies with a steep angle on the head above the snout. The small mouth is protrusible and is positioned low on the head. The teeth are set closely together and are moderately large, flattened and have serrated edges. They have 8 or 9 spines in the dorsal fin and 3 spines in the anal fin. The caudal peduncle has between 3 and 7 bony plates with sharp keels on each side.[6] The spined keels in the caudal peduncle are immobile in this genus compared to mobile ones in other surgeonfishes.[3] These fishes vary in their maximum published total lengths from 20 cm (7.9 in) in P. biafraensis to 70 cm (28 in) in P. microlepidotus.[5]
Prionurus have a predominantly Pacific range with six of the seven species being found in the Pacific Ocean,[5] two of these, P. laticlavus and P. punctatus being endemic to the eastern Pacific[6] and one, P. biafraensis, being endemic to the Eastern Atlantic.[5]
