Cophecheilus bamen, Zhu, Yu, Zhang, E, Zhang, Ming & Han, Yao-Quan, 2011

Zhu, Yu, Zhang, E, Zhang, Ming & Han, Yao-Quan, 2011, Cophecheilus bamen, a new genus and species of labeonine fishes (Teleostei: Cyprinidae) from South China, Zootaxa 2881, pp. 39-50 : 43-46

Cophecheilus bamen , new species

( Figs. 2 a, 3; Table 2)

Holotype: IHB 2000800009, 105.7 mm SL, a tributary flowing into Zuo-Jiang of Zhu-Jiang (Pearl River) drainage at Jingxi County, Guangxi, South China; coll. J.H. Lan July, 2008.

Paratypes: IHB 2000800010–7, 8, 65.3–84.5 mm SL, same data as holotype.

Diagnosis. See the generic diagnosis.

Description. Morphometric data for nine type specimens are given in Table 2. Body elongate, compressed laterally, with greatest depth at dorsal-fin origin and least depth of caudal peduncle slightly closer to caudal-fin base than to posterior end of anal-fin base. Dorsal profile of body gradually ascending from snout tip to dorsal-fin origin; from there to origin of dorsal procurrent caudal-fin rays profile slightly concave. Ventral profile from tip of snout to pectoral-fin insertion nearly straight; from there to anal-fin origin convex; anal-fin base straight; from posterior end of anal-fin base to origin of ventral procurrent caudal-fin rays slightly concave.

Head relatively small, longer than wide. Eye medium-sized with a wide, slightly convex interorbital space, dorsolaterally placed in anterior half of head. Snout blunt in lateral view and pointed in dorsal view, with a shallow groove running along anteroventral border of lachrymal from rostral-barbel base to lateral extremity of rostral cap; no tubercles on its tip and anterior portion of lachrymal. Two pairs of well-developed barbels; rostral barbel positioned at anterior end of shallow sublachrymal groove on each side of snout and extending to posterior margin of eye or not; maxillary barbel rooted in corner of mouth, originating from exterior surface of confluence between lateral lobe of lower lip and lateral extremity of rostral cap, and extending beyond posterior margin of eye to opercle. Mouth inferior and arched.

Dorsal-fin with four unbranched and 8* (9) branched rays, last one split to base; origin slightly nearer to tip of snout than to caudal-fin base; last unbranched ray longer than HL; distal margin slightly concave. Pectoral fin falcate, with one unbranched and 14 (1), 15* (6) or 16 (2) branched rays, inserted posterior to vertical through posterior-most point of opercle, reaching three-fourths of distance to pelvic-fin insertion and as far as third or fourth scale anterior to pelvic-fin insertion. Pelvic fin with one unbranched and 7* (9) branched rays, inserted vertically posterior to second branched dorsal-fin ray base, and extending to vent, but not to anal-fin origin. Anal fin with three unbranched and 5* (9) branched rays, last one split to base; distal margin slightly concave; origin placed equidistant between pelvic-fin insertion and caudal-fin base. Caudal deeply forked; upper and lower lobes equal in length and shape, with tapering rounded tips.

Body scales moderately sized; chest and belly scaled, scales slightly smaller than ones on flank. Lateral line complete, horizontal 43* (6), 44 (1) or 45 (1) plus three scales on caudal-fin base; scale rows above lateral line 7 (3) or 8* (6) and below 6 (3) or 7* (6). Predorsal scales 16 (4) or 17* (5), smaller than ones on flank, and anteriorly embedded under skin. Circumpeduncular scale rows 22* (9). Axillary scale present at pelvic-fin base, extending beyond base of last ray. Two scales between vent and anal-fin origin.

Vertebrae 41–42 (6) [26+15 = 41* (1), 25+16 = 41 (2), 26+16 = 42 (2), or 25+17 = 42 (1)]. Pharyngeal teeth triserial; tooth pattern 2, 3, 4–4, 3, 2 (1), with compressed and pointed tips ( Fig. 4 a). Gas bladder bipartite; anterior chamber oval, wider than posterior one; posterior chamber stick-like or elongate with an enlarged, rounded distal end, about twice as long as anterior one ( Fig. 4 b). Intestine long, forming many coils. Gill rakers on outer side of first gill arch 15–17 (4), short and small.

Color pattern in formalin. Top of head grayish brown, snout and lip grayish; cheek with sparse brownish pigments; opercle and subopercle brownish. Ground color of body grayish brown dorsally and laterally, yellowish white ventrally. An indistinct longitudinal black stripe, about one and half scales in width, originating near upper extremity of gill opening and terminating at caudal-fin base in a vertical bar extending along first scale row directly above lateral line anterior to vertical through anal-fin origin, thereafter along lateral line to caudal-fin base. Each scale on flank with dark chromatophores along exposed part of its posterior margin constituting a dark, crescentic, vertically-elongate mark; marks on scales above lateral line and directly below more prominent. Dorsal and caudal fins with dark chromatophores on fin rays, giving them a dusky appearance, and pectoral and pelvic fins with dark chromatophores on fin rays, more densely on anterior fin rays, giving them a dusky appearance. Anal fins hyaline.

Distribution. Known only from a tributary flowing into the Zuo-Jiang of the Pearl River drainage at Jingxi County, Guangxi Province, South China ( Fig. 5 ).

Etymology. The specific epithet, used as a noun in apposition, is made from Ba Men, the local name of this and similar species.

Figures

FIGURE 2. Ventral view of oromandibular structures in: (a) Cophecheilus bamen, IHB 2000800009, holotype, 105.7 mm SL; (b) Semilabeo notabilis, IHB 86082394, 167.1 mm SL, Hongshui-He of Pearl River drainage at Bama County, Guangxi Province; (c) Pseudogyrinocheilus prochilus, IHB 79 III 0068, 185.6 mm SL, upper Yangtze River drainage at Yibing City, Sichuan Province; (d) Parasinilabeo assimilis, IHB 75 IV 2445, 93.3 mm SL, Pearl River drainage at Xiuyun County, Guangxi Province.

FIGURE 4. (a) Left side of pharyngeal tooth plate in dorsomedial view, and (b) gas bladder in ventral view, of Cophecheilus bamen, IHB 2000800009, holotype, 105.7 mm SL.

FIGURE 5. Map showing the distribution of Cophecheilus bamen in Guangxi Province of South China.