Morphological and molecular study of the torrent catfishes (Sisoridae: Glyptosterninae) of Bhutan including the description of five new species.

Torrent catfishes of the subfamily Glyptosterninae from Bhutan are examined based on morphological and molecular data. Five new species are described: Creteuchiloglanis bumdelingensis sp. nov., Exostoma mangdechhuensis sp. nov., Parachiloglanis benjii sp. nov., P. dangmechhuensis sp. nov., and P. drukyulensis sp. nov. Molecular data derived from the mitochondrial gene Cyt b and the nuclear gene RAG2 recovered relationships within Parachiloglanis and the Glyptosterninae. A dichotomous key to the Glyptosterninae of Bhutan is provided.

A century in synonymy: molecular and morphological evidence for the revalidation of Glyptosternon osсhanini (Herzenstein, 1889) (Actinopterygii: Sisoridae).

Exostoma oschanini, presently treated as a junior synonym of Glyptosternon reticulatum, is revalidated within Glyptosternon based on a phylogenetic analysis of the CO1 gene and morphological characters. Glyptosternon oschanini is known to occur in tributaries of the Syr Darya River in Uzbekistan and Kyrgyzstan and may also occur in the Amu Darya River drainage. A morphological diagnosis and description are provided for G. oschanini. Exostoma gracile is a junior synonym of G. oschanini rather than of G. reticulatum.

Garra fluviatilis, a new hillstream fish species (Cypriniformes: Cyprinidae) from the Kwai Noi River system, Mae Khlong basin, Thailand.

Garra fluviatilis is a new species described herein from the Kwai Noi, Mae Khlong basin, in the Thong Pha Phum District of Kanchanaburi Province in western Thailand. It is diagnosed by the following combination of morphological characters: well developed upper lip with unculiferous papillae, mottled pigmentation pattern, a pleated papilliferous fold at the junction of the anterolateral lobe and anteromedial fold on the lower lip, 4-5 anal scales, relatively deep body, keeled nape, and a laterally straight anterior margin of the anteromedial fold. Based on shared apomorphic morphological characters, we hypothesize that the new species is most closely related to G. spilota in nearby Myanmar.

Garra robertsi, a new cyprinid (Cypriniformes: Cyprinidae) fish species from Borneo.

Garra robertsi is described from specimens collected from the Sungai Bongan and Tempassuk rivers in Sabah, Borneo. The species is differentiated from G. borneensis, its only congener on the island of Borneo, in having five (versus four) transverse scale rows above lateral line, the first branched dorsal-fin ray extending beyond the posterior-most extent of any other part of the dorsal fin when depressed (versus not extending posteriorly beyond last ray when depressed), breast with deeply embedded scales (versus exposed scales), fewer tubercles on snout, thin (versus thick) anteromedial fold on the lower lip, absence (versus presence) of a lateral stripe, absence (versus presence) of a stark, contrasting black stripe on lower caudal-fin rays, and other pigmentation characteristics.