Lan-Ping Zheng

The Sinocyclocheilus cavefish genome provides insights into cave adaptation

BackgroundAn emerging cavefish model, the cyprinid genus Sinocyclocheilus, is endemic to the massive southwestern karst area adjacent to the Qinghai-Tibetan Plateau of China. In order to understand whether orogeny influenced the evolution of these species, and how genomes change under isolation, especially in subterranean habitats, we performed whole-genome sequencing and comparative analyses of three species in this genus, S. grahami, S. rhinocerous and S. anshuiensis. These species are surface-dwelling, semi-cave-dwelling and cave-restricted, respectively.ResultsThe assembled genome sizes of S. grahami, S. rhinocerous and S. anshuiensis are 1.75 Gb, 1.73 Gb and 1.68 Gb, respectively. Divergence time and population history analyses of these species reveal that their speciation and population dynamics are correlated with the different stages of uplifting of the Qinghai-Tibetan Plateau. We carried out comparative analyses of these genomes and found that many genetic changes, such as gene loss (e.g. opsin genes), pseudogenes (e.g. crystallin genes), mutations (e.g. melanogenesis-related genes), deletions (e.g. scale-related genes) and down-regulation (e.g. circadian rhythm pathway genes), are possibly associated with the regressive features (such as eye degeneration, albinism, rudimentary scales and lack of circadian rhythms), and that some gene expansion (e.g. taste-related transcription factor gene) may point to the constructive features (such as enhanced taste buds) which evolved in these cave fishes.ConclusionAs the first report on cavefish genomes among distinct species in Sinocyclocheilus, our work provides not only insights into genetic mechanisms of cave adaptation, but also represents a fundamental resource for a better understanding of cavefish biology.

A new species of Genus Triplophysa (Nemacheilinae: Balitoridae), Triplophysa longipectoralis sp. nov, from Guangxi, China

A new species, Triplophysa longipectoralis, is described from Liujiang River, Guangxi, China. The new species is distinguished from other species of Triplophysa by the following combination of characters: pectoral fin highly developed, reaching beyond pelvic-fin origin; eyes present and vestigial; body covered with scales; dorsal and lateral sides of head and body mottled with blotches; dorsal fin emarginate; caudal fin forked; anus close to anal-fin origin. A key to all valid species of Triplophysa in Xijiang River water system is provided.

A new species of genus Pseudogyrinocheilus (Teleostei: Cyprinidae) from Guangxi, China

A new species, Pseudogyrinocheilus longisulcus, was discovered from a tributary of Pearl River in Jingxi Co., Guangxi, China, The new species can be distinguished from other species of Pseudogyrinocheilus by the following combination of characteristics: prolonged post-labial grooves, and extended antero-medially close to anterior end of middle lower lip, but not meeting with its counterpart; posterior margin of lower lip free; scales of abdomen from thorax to pectoral-fin base embedded under skin; lateral-line scales 40–42; dark stripe longitudinal along lateral line on flank. The key to the species of Pseudogyrinocheilus is provided.

Molecular systematics of the Labeonini inhabiting the karst regions in southwest China (Teleostei, Cypriniformes)

Abstract The major phylogenetic pattern of the cyprinid tribe Labeonini has been revealed by previous molecular studies; however, the relationships within a clade that mainly inhabits the karst regions, which we refer to as the “karst group”, in southwest China remain unresolved due to the low taxon sampling. This group includes more than 50% of the genera and species of Labeonini in China. Moreover, more than 90% of the genera of this group are endemic to China. In addition, some new genera and species of Labeonini have been discovered from these karst regions, but their taxonomic validity and phylogenetic position have not been examined. In this contribution, partial sequences of four nuclear (exon 3 of recombination activating protein 1, rhodopsin, early growth response protein 2B gene and interphotoreceptor retinoid binding protein gene) and three mitochondrial genes (cytochrome b, cytochrome oxidase subunit I and 16S ribosomal RNA) from 36 ingroup taxa and 25 outgroup taxa were analyzed to provide a hypothesis of the phylogenetic relationships within the labeonins of the karst regions in China. We propose that the monophyly of Parasinilabeo, Ptychidio, Rectoris and Semilabeo are supported. A new genus, Prolixicheilus, is erected for Pseudogyrinocheilus longisulcus. Cophecheilus bamen is the sister to Prolixicheilus longisulcus. Ptychidio, Pseudocrossocheilus, Semilabeo, Rectoris and Stenorynchoacrum are closely related with high support values. Sinocrossocheilus, Pseudogyrinocheilus, Paraqianlabeo, Hongshuia, Discogobio and Discocheilus form a clade together with high support. Considering molecular results and morphological differences, Parasinilabeo longicorpus and Ptychidio macrops might be the synonyms of Parasinilabeo assimilis and Ptychidio jordani respectively. Comprehensive taxonomic revisions of the two genera Parasinilabeo and Ptychidio may be necessary.

A new species of Triplophysa (Nemacheilidae: Cypriniformes), from Guangxi, southern China

A new species, Triplophysa huapingensis, is described from the Hongshuihe River, Guangxi, China. The new species is distinguished from other species of Triplophysa by the following combination of characters: body covered with scales, lateral line complete, eyes not degenerate, dorsal fin truncate, caudal fin forked, tip of pelvic fin not reaching anus, eight branched rays of dorsal fin, six branched rays of pelvic fin, 16 branched rays of caudal fin, grey and black diffused blotches on dorsal and lateral head and body. A key to all recorded species of Triplophysa in the Xijiang River system is provided.

A new species of the genus Triplophysa (Nemacheilinae: Balitoridae), Triplophysa jianchuanensis sp. nov, from Yunnan, China

A new loach species, named Triplophysa jianchuanensis, has been recognized in collections from Jianchuan in Dali Prefecture, Yunnan, China. Triplophysa jianchuanensis can be distinguished from the other Triplophysa species by the following combination of characteristics: smooth skin, scaleless; lateral line complete; head long (26.7–29.8% of SL); eyes large (25.9–31.0% of dorsal head length); snout shorter than postorbital length (26.9–30.1% of HL); middle of lower lip interrupted and forming a pair of furrows; lower jaw spoon-like with obtuse edge; posterior chamber of air bladder completely degenerated; intestines short, bending in zigzag-shape behind stomach; pelvic-fin tip not reaching anus; caudal fin emarginate; branched rays of dorsal fin 7; branched rays of caudal fin 16. A key to the known species of Triplophysa from the Lancangjiang River is provided.

A new genus and species of Labeonini (Teleostei: Cyprinidae) from the Pearl River in China

Zuojiangia jingxiensis, both a new genus and species, is described from the Pearl River in China. It is distinguished from all other genera and species of Labeonini by the unique combination of modified oromandibular structures and head skeleton: a well-developed, pendulous, and conspicuously arched rostral fold, with an entirely crenulated margin; prominent papillae densely covering the margin of the rostral fold and anterior part of the lower lip; long postlabial grooves, partitioning the lower lip into three parts; transverse branch of dentary longer than half the length of the longitudinal branch; stubby lateral process present at the anterolateral margin of the longitudinal branch of the dentary, close to the corner; in the upper jaw, the premaxilla bears a triangular ascending process tapering to a point; maxilla exhibits a pair of articular heads at the anterodorsal margin, and a distinct fingerlike descending process posterior to the medial articular head embracing the ascending process of the premaxilla.

Threatened fishes of the world: Anabarilius polylepis (Regan) 1904 (Cypriniformes: Cyprinidae)

Common name: Big white fish (English). Local name: Da Bai Yu, Tao Hua Bai Yu (Chinese). Conservation status: Anabarilius polylepis is one of the endangered fishes in Lake Dianchi (24°28′–25°28′N, 102°30′– 103°00′E, 1,886 m above sea level), Yunnan, China. IUCN Red List—Endangered. Identification: D III 7; A III 12–15; LL 66–78; circumpeduncular scales, 20–22; pharyngeal teeth 3 row. Body slender, average 200 mm SL. No barbels. Dorsal-fin slightly closer or equal to caudal-fin base than to snout tip. Caudal-fin forked, tips pointed. Coloration in fresh sliver white, dorsal body gray and brown, and lateral body reflecting light blue (Chen 1989; Luo and Chen, 1998; Regan 1904). Distribution: This species is endemic to Lake Dianchi and Songhuaba Reservior, Yunnan Province, China. Abundance: This species was common in the 1960’s, and from 1970’s, this species has been decreasing (Chen 1989). The population reduced 80% in the past three generations. It is now occasionally seen in Lake Dianchi and Songhuabai Reserivor. Habitat and ecology: It lives in the middle and upper layers of waters and mainly feeds on aquatic insects, plankton and fragments of plants. Threats: Introduced fish species (He et al. 1983; Gao et al. 1990), water quality, loss of macrophytes (in part due to grass carp), over-fishing, and breeding sites lost are likely the critical threats to A. polylepis. Reproduction: It turns sexually matured after one winter and the reproduction season is in March. It estimated that its generation length is about 5 years (Chen 1989). Conservation actions: The lake is closed for fishing for 5 months every year and 7 nofishing protected bay areas were set up, providing feeding grounds for some fishes in the lake, including A. polylepis. Conservation recommendations: A longterm monitoring and survey and artificial reproduction are required for survival of this endangered fish. Environ Biol Fish (2009) 85:229–230 DOI 10.1007/s10641-009-9484-5