Sincrossocheilus labiatus Su, Yang and Cui, 2003

Yuan, Le-Yang, Zhang, E & Huang, Yan-Fei, 2008, Revision of the Labeonine Genus Sinocrossocheilus (Teleostei: Cyprinidae) from South China, Zootaxa 1809, pp. 36-48 : 42-44

Sincrossocheilus labiatus Su, Yang and Cui, 2003

Figs. 2 B and 3B

Sinocrossocheilus labiatus Su, Yang & Cui, 2003: 420 (Tongzi River flowing to Chishui He at Tongzi County, Guizhou).

Material examined. KIZ 995338, holotype, 56.1 mm SL and KIZ 995330, 995333–5, 995340, paratypes, 5 ex., 49.2–72.7 mm SL; South China, Guizhou Province, upper Yangtz River drainage: Tongzi River flowing to Chishui He at Tongzi County (approximately 28º10’N, 106º48’E).

Diagnosis. A species of Sinocrossocheilus having a lower lip with a flattened crescentic fold, an inconspicuous longitudinal black stripe extending along lateral line on flank; no blotches on intermediate interradial membranes between dorsal-fin rays; no submarginal stripe extending along lobe of caudal fin; a shallow body (depth 17.4–22.6 [mean 18.9, SD 2.0] % SL); and a short snout (length 42.2–49.0 [mean 45.6, SD 2.5] % of HL).

Description. Morphometric data for five type specimens and one non-type specimen are presented in Table 1. See Figure 2 B for the morphology of oromandibular structures and Figure 3 B for general body appearance.

Characters of S. labiatus are similar to those of S. guizhouensis except as noted below. Dorsal body profile convex from tip of snout to dorsal-fin origin, straight from posterior end of dorsal-fin base to origin of dorsal procurrent caudal-fin rays. Ventral profile straight anterior to anal-fin origin; slightly concave from anal-fin origin to origin of ventral procurrent caudal- fin rays.

Eyes large, dorsolaterally positioned in middle of head; interorbital space wide, slightly flattish. Snout rounded when viewed dorsally, with many tubercles on tip of snout and anterior portion of lachrymal. Tubercles large, conical with pointed tips, irregularly organized in two rows. Both rostral and maxillary barbel lengths almost equal to eye diameter; rostral barbel slightly longer that maxillary.

Median lobe of lower lip large with its anterior and lateral margins modified into a flattened, densely papillated, crescentic fold anteriorly separated from lower jaw by a deep, arched, groove and posteriorly bordered with a fleshy pad in a shallow, arched groove; fleshy pad slightly protruded, covered densely with papillae.

Dorsal fin with 3 simple and 7 (6) branched rays, last one split to base; last simple ray longer than head length. Pectoral fin with 1 simple and 14 (6) branched rays. Pelvic fin with 1 simple and eight (6) branched rays, slightly shorter than head length; origin immediately posterior to vertical of third or forth branched dorsal-fin ray, or nearer to tip of snout than to caudal-fin base. Anal-fin with 3 simple and 5 (6) branched rays, last one spilt to base; origin closer to pelvic-fin insertion that to caudal-fin base.

Scales moderately large; lateral line complete, horizontal, 39 (2), 40 (1), 41(1) or 42(1) plus 3 scales on caudal-fin base; 1/2 5/1/4 1/2 (6) scales in transverse row anterior to pelvic fin; predorsal midline scales smaller than those on flank, irregularly arranged; circumpeduncular scales 14 (5) or 16 (1). Gas bladder bipartite, anterior chamber oval and posterior chamber slender, 1.5–2.5 times as long as anterior one. Pharyngeal teeth biserial, tooth pattern 3, 5–5, 3 (2), with compressed and pointed tips.

Colour pattern in alcohol. Head and body yellow dorsally and laterally, and pale yellow ventrally. Each scale on back and flank yellow with many black spots on its posterior margin, forming a reticulated pattern. A distinct black bar on upper half of flank immediately above fifth lateral line scale. An inconspicuous longitudinal black stripe running along lateral line from upper extremity of gill opening to caudal-fin base and ending in a large black bar on caudal-fin base, anteriorly slightly wider and posteriorly slightly narrower. Dorsal- and pectoral-fin rays black; caudal fin with a submargin stripe along lobe; all other fins yellow.

Distribution. Sinocrossocheilus labiatus is so far known only from the Tongzi River, a tributary to the Chishui He of the upper Yangtze River drainage, at Tongzi County, Guizhou Province, South China ( Fig. 4 ).

Remarks. In the original description by Su et al. (2003), S. labiatus has eight branched dorsal-fin rays. However, our examination of the type specimens showed that there are seven branched dorsal-fin rays. It is likely that the last branched ray that is split down to its base was counted by Su et al. (2003) as two rays, but by us as a single ray.

The species name ending (- a) of this species is incorrect. The epithet name of this species is actually derived from a Latin world ‘ labiatus ’. Sinocrossocheilus is masculine and requires that its specific name agrees in gender with the generic name. Thus, the correct epithet name of this species is labiatus rather than labiata.

Figures

FIGURE 2. Ventral view of lower lip morphology in: (A) Sinocrossocheilus guizhouensis, IHB 6650508, lectotype, 59.0 mm SL; (B) Sinocrossocheilus labiatus; KIZ 995338, holotype, 56.1 mm SL; (C) Hongshuia paoli, IHB 200210911, holotype, 54.3 mm SL; (D) Hongshuia microstomatus, IHB 87 IV 506, paratype, 81.7 mm SL; (E) Pseudocrossocheilus bamaensis, IHB 85 VII 056, 152.9 mm SL; (F) Pseudocrossocheilus tridentis, KIZ 774079, holotype, 118.0 mm SL. cf = crescentic fold of median lobe of lower lip; fp = fleshy pad of median lobe of lower lip; mb = median lobe of lower lip; rlf = ring-like fold of median lobe of lower lip.

FIGURE 3. Lateral view of: (A) Sinocrossocheilus guizhouensis, IHB 6650508, lectotype, 59.0 mm SL; (B) Sinocrossocheilus labiatus; KIZ 995338, holotype, 56.1 mm SL; (C) Hongshuia paoli, IHB 200210911, holotype, 54.3 mm SL.

FIGURE 4. Map showing distributions of two species of Sinocrossocheilus in South China.