Two new gobiid fish species (in Priolepis and Trimma) from the Chagos Archipelago, central Indian Ocean

Abstract

Priolepis compita n. sp. is described from specimens from the Chagos Archipelago, but other material indicates an Indo-west Pacific distribution from South Africa to Fiji. Trimma emeryi n. sp. was described and illustrated in colour by Winterbottom in 1984 under the name T. mendelssohni, with a note added in proof stating that it was not that species but represented an undescribed form. Priolepis and Trimma are closely related, differing mainly in the anteroventral extent of the gill opening and in colour pattern. The new Priolepis differs from its congeners in having the vertical bars on the postocular portion of the head and the nape joined by a horizontal line, sometimes staggered, at the level of the dorsal margin of the pupil. Its distribution includes the Kwazulu coast of southern Africa to at least Fiji in the western Pacific. The new Trimma differs from other species in the genus in colour pattern, a number of meristic characters, and in details of fin-ray branching patterns. The new species is recorded definitely only from Chagos and the Gulf of Tadjoura in the Gulf of Aden. Specimens from Fiji apparently represent a closely related species.