Gladius sea chub

Kyphosus gladius has an elongated, elliptically-shaped body with a terminal mouth and a short head.[2] There are 55-64 scales in the lateral line of which 44-55 are pored.[3] The caudal peduncle is long and shallow. Most of the head and body is covered in large, ctenoid scales.[2] The continuous dorsal fin has 10 - 11 spines and 11-12 soft rays and the short-based anal fin has 3 spines and 11-12 soft rays.[1] The overall colour is silvery to metallic bluish, the gill cover has a vertical green bar near its rear and the back is darker than the underparts, although this is not seen as counter-shading.[3] The standard length of the largest fish measured is 45.7 centimetres (18.0 in).[1]

Kyphosus gladius is found in the southeastern Indian Ocean where it is endemic to the southern coasts of Western Australia. The distribution runs from the Houtman Abrolhos to Albany.[3]

Kyphosus gladius occurs over rocky substrates down to depths of 20 metres (66 ft). It will form mixed schools with Kyphosus bigibbus and Kyphosus sydneyanus.[2]

Kyphosus gladius was described in 2013 by Steen Wilhelm Knudsen and Kendall D. Clements with the type locality given as Canal Rocks, Yallingup Reef, Western Australia.[4] It has previously been confused with K. sydneyanus, Knudsen and Clements showed that this was a separate species, although previously another species named Kyphosus klunzingeri has been named from Western Australia but this is now regarded as a nomen dubium.[2]