Kyphosus cinerascens is a fish belonging to the class Actinopterygii, the order perciformes and the family Kyphosidae. It is a species found in shallow waters as well as in the tidal channels of the reefs of the Indian and Pacific oceans up to 30 meters deep. It usually lives on rocky bottoms or upholstered by algae.
The body of Kyphosus cinerascens reaches a maximum total length of 50 cm, has an oval shape and is laterally compressed. It has a short snout with a pronounced profile. Its preoperculum has finely serrated edges, and the operculum has a blunt spine. The dorsal fin is unique, located along the posterior two thirds of the body and has a region with 11 spines followed by a region with 12 soft rays (rarely 11 or 13). Of the spiny region, its base is longer than the base of the soft ray portion, and the sixth or seventh spine is higher than the rest. Of the soft part of the dorsal fin, we note that it is distinctly higher than the largest of the spines of the dorsal fin, a fact that also occurs in the anal fin. The anal fin is formed by 3 spines, the last one being the longest of the three. The spines of the anal fin are followed by 10-12 soft rays, which, as previously mentioned, are taller than the spiny region of the anal fin. The pectoral fins have 17-19 rays, and the caudal fin, which has a long caudal peduncle, is slightly forked.
Kyphosus cinerascens has a dark gray body with a bluish tint that is lighter on the underside of the body. The edge of the scales are dark, giving it the appearance of dark longitudinal lines on its flanks. They also have a completely silvery stripe under the eye, reaching the operculum. The fins are usually dark brown.
It is common to observe this species forming schools of individuals of the same species in surface waters, especially during daylight hours. During the night, they are a more solitary species and usually swim near the seabed. The diet is herbivorous in nature, although occasionally complemented with some benthic invertebrates.
In appearance they are very similar Kyphosus cinerascens and Kyphosus vaigiensis. To differentiate between the two we will focus on the dorsal fin. Kyphosus vaigiensis usually has 14 soft rays, and they never exceed the height of the longest spine of its dorsal fin.Photos: