Description

This is a medium-sized goby measuring around 7 cm. It occurs in a golden and a dark form. 

Body design 

The golden form has a yellow background colour, darker on top and paler below. The only markings are the blue-white facial markings which extend on the upper portion as far back as the first dorsal fin, and faint narrow bands along the body. 

The brown form has a grey background colour with the same spots and some dark bars, the most constant being an oblique band from the front of the dorsal fin over the posterior aspect of the gill cover and a dark bar at the level of the back of the first dorsal fin, behind this are six narrow white bars equally spaced back to the caudal peduncle. The spaces between them may be filled making more dark bars or the dark colour may just intensify towards the tail. 

Basically, the two forms have the same pattern but this is obscured in the rather albinotic yellow form and increasingly accentuated in individuals with increasing amounts of melanotic pigment. 

Face design

The head of the golden form is yellow, darker from snout to nape, with blue-white spots evenly scattered over the pale zone as far back as the pectoral fin. The head of the dark form has the same design except that the background colour is grey and the dark zone is much darker to the point that the jaw, snout, eyes and nape may be black. 

Fin design

In the golden form, the first dorsal fin is yellow with rows of blue-white spots along the fin membranes. The pattern is somewhat different in the dorsal fin of the brown form where against a background of pale grey there are four or five darker grey arcs. The membrane between these arcs may be plain or each membrane may be highlighted by lines of white spots, similar to those seen in the yellow form, creating a series of broken arcs between the dark ones. Each fin ray has a black tip. 

The second dorsal fin has the same design in both forms apart from the grey or yellow background, Each fin ray membrane has a row of three white spots followed by a dark streak. 

The pelvic fin is yellow or dark grey depending on the colour form. This is covered in small blue-white spots. The anal fin is opaque yellow or grey. The caudal fin is yellow or grey and plain apart from faint streaking. The pectoral fins are transparent apart from the base which is yellow or grey with blue-white spots. 

Diagnostic features

The main problem is telling this apart from Cryptocentrus fasciatus, The dorsal fin markings are useful: fine spots in the golden form and a series of arcs in the brown one. 

Similar species

Cryptocentrus fasciatus, which has several forms some resembling C cinctus. but do not have spots on the dorsal fin. 

Cryptocentrus sericus, has arcs, not spots, on the first dorsal fin. and a spotted pelvic fin. The defining characteristic is the barred pelvic fin, 

All three have a brown and a golden form.