Description

Body design

A small goby, around 5. 5 cm, white with many oval and circular brown patches arranged in defined lines along the body. There is a large circular brown patch on the base of the tail. There is a series of white spots along the dorsum. These are surrounded by tiny blue reflective spots.

The head is decorated with a series of broken diagonal lines covering the area from the nose to the gill covers.

Fin design

All the fins are transparent with darker markings on the fin rays. The caudal fin has one or two random brown spots. There are narrow white streaks along the midpoint of the pectoral fin.

Diagnostic features

This is a very recognisable species.

The main diagnostic feature is the pattern of orange lines on the cheek.

The dark spot on the base of the tail may also be useful but it is present in less pronounced form in other species.

Similar species

The species of Ctenogobiops may be difficult to tell apart. Apart from C tangaroai, with its distinctive dorsal fin, they are differentiated by head and body patterns.

Head patterns

C aurocingulus has 16 bright orange markings in four rows of four in the shape of a trapezoid starting at the angle of the jaw

C feroculus has no head pattern.

C crocineus has a series of broken diagonal lines covering the whole area from the nose to the gill covers.

C mitodes has three spots in a straight line along a skin fold running back and upwards from the angle of the mandible

C pomastictus has three spots curving ventrally, running back from the angle of the mandible. Above these, three spots in a horizontal straight line below the level of the eye.

Body patterns

C aurocingulus has fine gold bars running through lateral patches

C feroculus has poorly defined lateral patches only

C crocineus has lateral decoration arranged in parallel lines

C mitodes have small brown spots below the level of lateral patches

C pomastictus has dark-outlined orange spots below patches

Nomenclature

Cryptocentroides crocineus by Fourmanoir 1955

Previously confused with Ctenogobiops maculosus from the Red Sea. This species differs by having a horizontal line on the face. C. crocineus has vertical lines on the face down to the lips. 

Thacker (2010) makes C maculosus and C crocineus into two species by phylogeny using only one example of each and not defining how they were told apart morphologically. Her morphological characters for the two species are identical and the photographs provided are unusable.

Kovacic, Bogorosky and Randall (2011) Confirmed the validity of C crocineus from a morphological study and comparison of live photographs. They consider that C maculosus is restricted to the Red Sea while C crocineus is found in the Red Sea, the Indian Ocean Islands, and through Indonesia to the Pacific Ocean (records from the Great Barrier Reef, Ryukyu Islands and Fiji).

Other Common Names: Crocus Shrimpgoby, Saffron Shrimp-goby, Seychelles Shrimpgoby.

Etymology:

The specific name crocineus is from the Latin crocum (= saffron spice), in reference to the orange-yellow colour of this species as depicted in the illustration of the holotype.