Sinocrossocheilus Wu

Sinocrossocheilus Wu in Wu, Lin, Chen, Chen & He, 1977

Type species: Sinocrossocheilus guizhouensis Wu in Wu, Lin, Chen, Chen & He, 1977.

Diagnosis. Sinocrossocheilus can be easily separated from all other Asian genera of the Labeonini sensu Reid, 1982 by the presence of a lower lip with its median lobe modified into a densely papillated, greatly protruded, crescentic fold, and a papillated, somewhat protruded, triangular fleshy pad that is posteriorly continuous with the mental region (Fig. 1 A). It is separated from all other Asian Labeonini fishes with the exception of Hongshuia Zhang, Xin & Lan, 2008 (type species: Hongshuia paoli Zhang, Xin and Lan, 2008), all species of Parasinilabeo Wu in Wu, Lin, Chen, Chen & He, 1977 (type species: Parasinilabeo assimilis Wu & Yao in Wu, Lin, Chen, Chen & He, 1977) exclusive of P. longibarbus Zhu, Lan & Zhang, 2006, which has eight branched dorsal-fin rays, and Qianlabeo Zhang & Chen, 2004 (type species: Qianlabeo striatus Zhang & Chen, 2004) by possessing seven (vs. no fewer than eight) branched dorsal-fin rays.

Among Asian Labeonini genera, Sinocrossocheilus is most similar to Hongshuia, with which it shares a papillose, crenulated rostral fold that is disconnected from the lower lip at the corners of the mouth, welldeveloped maxillary barbels, seven branched dorsal-fin rays, and two rows of pharyngeal teeth. Both differ in the details of lower lip morphology (Figs. 2 A–D) and in colour pattern (Figs. 3 A–C). In Sinocrossocheilus, the median lobe of the lower lip possesses a crescentic (vs. ring-like in Hongshuia) fold capping (vs. surrounding) the slightly protruded (vs. flat), roughly triangular (vs. round) fleshy pad; the posterior (vs. posteromedian) margin of the fleshy pad (vs. ring-like fold) is posteriorly continuous with the mental region. And a conspicuous black bar on the upper half of the flank immediately above the fifth lateral line scale is missing in Hongshuia, but present in Sinocrossocheilus.

Sinocrossocheilus is further separated from both Qianlabeo and Parasinilabeo by having a rostral fold disconnected (vs. connected) from the lower lip at the corners of the mouth, two (vs. three) rows of pharyngeal teeth, and by lacking postlabial grooves (vs. present only in the sides of the lower jaw in Parasinilabeo, or prolonged anteromedially, but not meeting with its counterpart at the midline in Qianlabeo); from all species of Parasinilabeo exclusive of P. longibarbus by the presence of well-developed (vs. none or minute) maxillary barbels; and from Qianlabeo by lacking an upper lip (vs. present only in and completely adnate to the side of the upper jaw) (vs. present). For the morphology of oramandibular structures of Qianlabeo and Parasinilabeo, see Zhang & Chen’s (2004: 30), figs.1(c)–(d), respectively.