Three new snow trout described

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Chinese ichthyologists have described three new species of snow trout in a paper published in a recent issue of the journal Zootaxa.

Jian Yang, Xiaoyong Chen and Junxing Yang named the cyprinids Schizothorax nudiventris, S. heterophysallidos, and S. beipanensis from material previously identified as S. griseus.

Schizothorax beipanensisThis species is known from the Beipan River drainage (part of the Pearl River drainage in southern China), after which it is named.

It is distinguished from congeners in lacking a horny sheath on the lower jaw, having well-developed upper and lower lips, with the lower lip tri-lobed, and a continuous postlabial groove bearing a minute median lobe.

It differs from S. griseus in lacking black spots on the sides of the body, having a soft last one-quarter to one-fifth of the last unbranched dorsal-fin ray, rostral barbel not reaching the middle of the eye and eye diameter 58.5'120.1% of the length of the maxillary barbel.

Schizothorax beipanensis has been found in slow-flowing deep pools and clear, fast-flowing rivers, with substrates ranging from mud, sand and rocks to sand, pebbles and boulders.

Schizothorax heterophysallidosThis species is known from the Nanpan River drainage (part of the Pearl River drainage in southern China), and differs from congeners in having a blunt snout, thin upper lip, well-developed and trilobed lower lip, continuous postlabial groove bearing a minute median lobe, scaleless abdomen in mature individuals, strong lower part of the last unbranched dorsal-fin ray, with 15'23 serrae on its posterior edge, pelvic-fin origin beneath or in front of a vertical line through the dorsal-fin origin, eye diameter 57.2"160.0% of maxillary-barbel length, and posterior chamber of air bladder three to six times longer than that of anterior one.

Schizothorax heterophysallidos is found in small streams with a substrate of sand and pebbles. The species is named after its unusual swim bladder morphology (from the Greek heteros=different and physallis=bladder).

Schizothorax nudiventrisThis species is known from the upper Mekong River drainage in southern China, and differs from congeners in having a blunt snout, thin upper lip, well-developed and trilobed lower lip, continuous postlabial groove, scaleless abdomen in mature individuals, soft last one-quarter of the last unbranched dorsal-fin ray, first three-quarters of it strong, with 15'21 serrae along its posterior edge, pelvic-fin origin beneath or behind a vertical line through the dorsal-fin origin, and irregular black spots on the sides of the body.

Schizothorax nudiventris is named after its scaleless abdomen (latin nudus=naked and venter=abdomen).

For more information, see the paper: Yang, J, X-Y Chen and J-X Yang (2009) The identity of Schizothorax griseus Pellegrin, 1931, with descriptions of three new species of schizothoracine fishes (Teleostei: Cyprinidae) from China. Zootaxa 2006, pp. 23"40.