Modern accumulations of genetic data offer unprecedented opportunities for understanding the systematic classification and origins of specific groups of organisms. The genusSinocyclocheilusis among the most cave abundant genera in Cyprinidae, with 76 recognized species, belonging to 4 species groups. Recent phylogenetic studies have shown that the classification of species groups within the genusSinocyclocheilusremains controversial. In this study, we constructed a sequence supermatrix of 26 species from 4 species groups of the genusSinocyclocheilususing the mitochondrial genome to reveal phylogenetic relationships, historical biogeography and patterns of species diversification in the genusSinocyclocheilus. Phylogenetic analysis strongly supports the monophyletic groups of the 3 species groups (S. jii,S. cyphotergous, andS. tingigroups) except theS. angularisgroup. Phylogenetic analysis showed thatS. anshuiensisandS. microphthalmus, which were recognized as numbers ofS. angularisgroup, formed a strongly supported independent clade. Therefore, we propose a new species group, theS. microphthalmusgroup, which containsS. anshuiensisandS. microphthalmus. Biogeographic reconstruction suggests that the livingSinocyclocheilusmay have originated in north‐central Guangxi at the late Eocene and dispersed outward after a vicariance at 32.31 Million years ago (Ma). Early diversification is focused on the late Oligocene (ca. 25 Ma), which is related to the second uplift of the Qinghai−Tibetan Plateau and the lateral extrusion of the Indochina at the Oligocene/Miocene boundary. Our results suggest that 2 uplifts of the Qinghai−Tibetan Plateau and climate change in the Miocene may have influenced the diversification of theSinocyclocheiluslineage.

This study describes a new species of the genus Leptobrachella, Leptobrachella suiyangensis sp. nov. from the Huoqiuba Nature Reserve, Suiyang County, Guizhou Province, China, based on morphological data and phylogenetic analyses (16S rRNA mtDNA). The new species can be distinguished from other congeners by the molecular divergence and by a combination of morphological characters, including body size, dorsal and ventral patterns, dorsal skin texture, size of the pectoral and femoral glands, degree of webbing and fringing on the toes and fingers, dorsum coloration, and iris coloration in life. Currently, the genus Leptobrachella contains 75 species, 21 of which are found in China, including seven species reported from Guizhou Province. The uncorrected sequence divergence percentage between Leptobrachella suiyangensis sp. nov. and all homologous DNA sequences available for the 16S rRNA gene was found to be >4.7%. The new record of the species and its relationships with others in the same genus imply that species distribution, habitat variation, environmental adaptation, and diversity of the genus Leptobrachella in southwest China need to be further investigated.

Sinocyclocheilus longicornussp. nov.is described from the Pearl River basin in Hongguo Town, Panzhou City, Guizhou Province, Southwest China. Based on the presence of the long horn-like structure on the back of the head,Sinocyclocheilus longicornussp. nov.is assigned to theSinocyclocheilus angularisspecies group.Sinocyclocheilus longicornussp. nov.is distinguished from its congeners by a combination of morphological characters: (1) presence of a single, relatively long horn-like structure on the back of the head; (2) pigmentation absent; (3) reduced eyes; (4) dorsal-fin rays, ii, 7; (5) pectoral-fin rays, i, 13; (6) anal-fin rays, iii, 5; (7) pelvic-fin rays, i, 7; (8) lateral line pores 38–49; (9) gill rakers well developed, nine on first gill arch; and (10) tip of adpressed pelvic fin not reaching anus.

Nostril structures are important characteristics for generic diagnosis in Nemacheilidae and Cobitidae. Based on phylogenetic analysis, we found that 10 genera within Nemacheilidae (Eonemachilus, Guinemachilus, Lefua, Micronemacheilus, Oreonectes, Paranemachilus, Protonemacheilus, Traccatichthys, Troglonectes, and Yunnanilus) shared tube-shaped anterior nostrils and formed a monophyletic group. Morphologically, the location between the anterior and posterior nostrils was divided into three types: (i) separated, i.e., a distance greater than 1.5 times the diameter of the posterior nostril; (ii) adjacent, i.e., a distance shorter than the diameter of the posterior nostril; and (iii) closely set, i.e., posterior margin of the anterior nostril connected to the anterior margin of the posterior nostril. Thus, the 10 genera can be distinguished based on nostril features. Additionally, we describe one new genus, Guinemachilus gen. nov., and two new species, Guinemachilus pseudopulcherrimus sp. nov. and Paranemachilus chongzuo sp. nov.

Recently described cave species of the genus Triplophysa have been discovered in southwestern China, suggesting that the diversity of the genus is severely underestimated and that there may be many undescribed species. In this work, four new species of the genus Triplophysa are described from southwestern Guizhou Province, China, namely Triplophysa cehengensis Luo, Mao, Zhao, Xiao & Zhou, sp. nov. and Triplophysa rongduensis Mao, Zhao, Yu, Xiao & Zhou, sp. nov. from Rongdu Town, Ceheng County, Guizhou, Triplophysa panzhouensis Yu, Luo, Lan, Xiao & Zhou, sp. nov. from Hongguo Town, Panzhou City, Guizhou, and Triplophysa anlongensis Song, Luo, Lan, Zhao, Xiao & Zhou, sp. nov. from Xinglong Town, Anlong County, Guizhou. These four new species can be distinguished from all recognized congeners by a combination of morphological characteristics and significant genetic divergences. The discovery of these species increases the number of known cave species within the genus Triplophysa to 39, making the genus the second most diverse group of cave fishes in China after the golden-line fish genus Sinocyclocheilus. Based on the non-monophyletic relationships of the different watershed systems in the phylogenetic tree, this study also discusses the use of cave species of the genus Triplophysa to determine the possible historical connectivity of river systems.