Description

Body design

This very small goby grows to around 2. 5 cm in length. It is pale blue-grey with two rows of yellow spots laterally. Between these is a brilliantly reflective blue streak. About the level of the anus, the spots are replaced with yellow lines on either side of the blue streak. These are not always visible. The underside of the body is plain and cream-coloured.

four vertical brown bars on the body are described and illustrated in the type description but we have not seen these.

Head design

The cheek is plain with two brown blotches, one below the eye and one on the gill cover. An iridescent blue bar extends from below the eye to the angle of the jaw and another to the operculum. A vertical black bar which varies in intensity crosses the pupil. The snout and upper lip are bright yellow with a black streak above the upper lip.

Fin design

Apart from the caudal fin the fins usually appear translucent and unmarked. The true pattern is best seen when the goby is displaying, The first dorsal fin then has two rows of yellow spots on a background of pale blue with a pale yellow edge. It. is a low rectangle with no extended rays. The second dorsal fin is decorated with a single line of brighter yellow-green spots. The caudal fin is pale yellow with a blue margin and the sword-shaped central rays blue with a brighter yellow border, itself having a blue outline. It is large and triple-pointed. The anal fin is creamy with a yellow subterminal stripe. The pelvic fin is pale yellow.

Diagnostic features

Distinguished from other Vanderhorstia by:

Low first dorsal fin with third to fifth spinous rays about equal.

The caudal fin large with a sword-like projection of middle rays

Specific colouration: Blue stripe with a row of yellow spots anteriorly