Troglocyclocheilus khammouanensis, a new genus and species of cave fish from the Khammouan karst, Laos (Teleostei: Cyprinidae)

Abstract

Troglocyclocheilus khammouanensis, new genus, new species, is distinguished by the absence of externally visible eyes, the presence of several rows of sensory papillae on the head, the shape of the mouth, lips and rostral fold, the slender and smooth last simple dorsal ray, and the lateral line scales with a notch on the posterior margin. Other southeast and east Asian cave cyprinids are discussed. The sensory function of the 'parietal processes' or 'parietal organs' of some species of Sinocydocheilus (and its synonym Gibbibarbus] is doubted and an hydrodynamic function is hypothesized instead. The publication dates and authorship of S. hyalinus, Protocobitis and P. typhlops are discussed and lectotypes are designated for S. hyalinus and P. typhlops. Barbus speleops from Tham Phu Khieo, Thailand, belongs to the genus Poropuntius (nov. comb.).