Maurice Kottelat

Abstract. Microcobitis stilaspi, new species, is described from the Nakai Plateau and Nam Theun watershed, a tributary of the Mekong, in central Laos. It is a small-sized species (largest known specimen 42.4 mm SL) distinguished from its single congener (M. misgurnoides) in having, in males, the post dorsal body conspicuously twisted upwards, then horizontal again, with a mid-dorsal swelling forming a protuberance above the end of the base of the anal fin; in males, the pectoral fin reaching about ½ to ⅗ of distance to pelvic-fin origin; two black spots at the base of the caudal fin; the origin of the pelvic fin under the base of branched dorsal-fin rays 1–3. The species was collected in the mud in drying pools, swamps and buffalo wallows. The diagnosis of the genus Microcobitis is updated, with addition of sexual dimorphism.

Key words. Cobitoidei, Mekong River, sexual dimorphism

Read article here: RBZ-2025-0040