Vanmanenia maculata, Yi, Wen-Jing & Shen, Jian-Zhong, 2014

Yi, Wen-Jing & Shen, Jian-Zhong, 2014, Vanmanenia maculata, a new species of hillstream loach from the Chang-Jiang Basin, South China (Teleostei: Gastromyzontidae), Zootaxa 3802 (1), pp. 85-97 : 86-92

Vanmanenia maculata sp. nov.

( Figs. 2 and 3 B, Table 1)

Vanmanenia pingchowensis: Xie et al., 1984: 62 (Qing-Jiang of middle Chang-Jiang basin, Hubei Province); Yang, 1987: 142 (Lushui-He at Tongcheng County, and Qing-Jiang at Lichuan and En’shi counties, Hubei Province); Chen, 1989: 126 (Li- Shui at Suoxiyu nature preserve area); Zhang et al., 1996: 3 (Xin-Jiang at Shangrao, Jiangxi Province); Ding, 1994: 424 (You-Shui at Xiushan, Chongqing City).

Holotype. IHB 200606059, 62.8 mm SL; Majia-He, a tributary flowing into Qing-Jiang of Chang-Jiang basin, at Enshi County, Hubei Province, South China; E Zhang; June, 2006.

Paratypes. IHB 200606061-62, 6080, 6087, 6127, 5 specimens, 42.0– 62.8 mm SL; other data same as for holotype; IHB 81IX 0356, 0676-0678, 0682-0683, 0696-0700, 0 840, 12 specimens, 57.8–80.2 mm SL, Qing-Jiang of middle Chang-Jiang basin at Yidu City, Hubei Province; IHB 82V 1222, 1244, 1248, 1252, 4 specimens, 49.0– 78.8 mm SL; Qing-Jiang of middle Chang-Jiang basin at Changyang County, Hubei Province; IHB 1983IX 1426, 1798, 1800-02, 1804, 1806-08, 1810, 1814, 1816, 1818, 1822, 14 specimens, 50.4–78.0 mm SL, Li- Shui (a tributary of Dongting Lake system in Cili County) at Suoxiyu Natural Resource Reserve of Zhangjiajie City, Hunan Province.

Non-types. IHB 2012120236, 2012120267-68, 2012120270, 4 specimens, 48.8-80.3 mm SL, Xin-Jiang, a tributary of Poyang Lake system in lower Chang-Jiang basin, at Tongboshan County, Jiangxi Province.

Diagnosis. Vanamnenia maculata resembles V. caldwelli , V. stenosoma , and V. s t r i a t a, in having no secondary rostral barbels ( Figs. 3 A–B), by which these four species are readily distinguished from all other Chinese congeneric species: V. gymnetrus , V. hainanensis , V. homalocephala , V. lineata , V. pingchowensis , V. polylepis , and V. xinyiensis ( Figs. 3 C–D). It is distinct from V. caldwelli and V. striata in having a rostral fold with three triangular vs. rounded lobules, a more posteriorly vs. anteriorly placed anus, with the distance between the anus and the analfin origin 29.5–45.5 vs. 46.3–63.0% of the distance between the pelvic-fin insertion and the anal-fin origin. It is further distinguished from V. caldwelli in the absence (vs. presence) of a longitudinal black stripe running from the snout tip to the caudal-peduncle base along the lateral line on the side of the body, and from V. s t r i a t a in the possession of white-centered dark rings or irregular dark vertical bars vs. 19–23 regular parallel vertical bars on the side of the body. It differs from V. stenosoma in having a larger scaleless area on the ventral surface of the body (scales missing on the anterior two-thirds or more vs. at most one-third of the chest and abdomen between the pectoral- and pelvic-fin insertions), and a shallower vs. deeper caudal peduncle (CPD 0.92–1.38 vs. 0.63–0.84 in CPL).

Description. Meristic and morphometric data for type specimens are given in Table 1. Body shape and coloration pattern are presented in Figures 2 and 3 B. Body elongate, with greatest body depth immediately anterior to dorsal-fin origin; head and predorsal region moderately depressed; trunk after dorsal-fin origin and caudal peduncle compressed. Dorsal profile of body convex. Ventral profile of head flattened, from pectoral-fin insertion to pelvic-fin origin slightly convex, and from anal-fin origin to caudal-fin base slightly convcave. Caudal peduncle stout, as deep as long or sometimes slightly deeper than long.

Head depressed in lateral view. Snout obtuse in dorsal view and longer than postorbital length. Eyes small, supralateral in lateral view, invisible from underside of head. Interorbital space broad and flat. Anterior and posterior nostrils separately set, and short flap on anterior nostril. Mouth small, inferior and horseshoe-shaped. Deep groove present between rostral fold and upper lip. Lips fleshy and thick; upper lip pendulous, covered with indistinct small papillae, connected with lower lip around corner of mouth by papillous flap; lower lip with four large papillae, two median ones more anteriorly positioned and usually bigger than lateral two; postlabial groove short, and restricted to corner of mouth on chin. Upper and lower jaws bearing thick, flexible horny sheaths on cutting edges. Rostral fold divided into three triangular lobules; median one wider than two lateral ones; distal edge of each tubule smooth. Two pairs of rostral barbels; outer pair larger than inner pair. Pair of maxillary barbels at corners of mouth ( Fig. 3 B). Gill opening reaching ventral surface of head for short distance in front of pectoral-fin insertion. Scales minute, cycloid. Lateral-line complete with 87–98 perforated scales, slightly curved upwards for half of pectoral-fin length, then downwards to posterior end of anal-fin base, extending along middle of caudal peduncle. Scales absent on anterior two-thirds or more of chest and abdomen, to between pectoral- and pelvic-fin insertion. Vertebrae 4 + 33 (30) or 34 (6).

Dorsal fin with 3 simple and 7 1/2 (36) branched rays, almost as long as head; origin anterior to pelvic-fin insertion, closer to caudal-fin base than to snout tip; distal edge slightly concave. Paired fins horizontally placed. Pectoral fin with 1 simple and 13 (36) branched rays, much longer than head; inserted slightly behind lower extremity of gill-opening; tip of adpressed fin not reaching pelvic-fin insertion. Pelvic fin with 1 simple and 7 (36) branched rays; inserted closer to caudal-fin base than to snout tip; tip of adpressed fin exceeding anus, but separated from anal-fin origin; distal margin round; axillary lobe present at pelvic-fin base. Anal fin with 2 simple and 5 1/2 (36) branched rays; last one split to base; origin nearly midway between pelvic-fin insertion and caudal-fin base; distal edge convex. Anus located midway from posterior end of pelvic-fin base to anal-fin origin or slightly behind. Anal fin extending to ventral origin of procurrent rays of caudal fin. Caudal fin shallowly emarginated with lower lobe slightly longer.

Color in preservative. Color of head and body yellowish. Top of head, cheek, and side of snout with numerous, small, irregular, brown bars and blotches. Body with 7–9 (3–4 predorsal, 1 subdorsal and 3–4 postdorsal) brown saddles and an indistinct black stripe extending along lateral line on flank in adult specimens, but a more conspicuous stripe in small specimens. Predorsal saddles much wider than interspaces, but subdorsal and postdorsal ones approximately as wide as interspaces. Above the lateral line, a number of irregular brown blotches, nearly unconnected with predorsal and subdorsal saddles, but linked to postdorsal saddles. Brown blotches present below the lateral line. Brown bar above anal-fin origin extending downwards to ventral surface of body. Brown blotch through pelvic-fin insertion extending down to base of axillary lobe at pelvic-fin base. Dorsal fin hyaline with 3 or 4 black bands across rays, anal fin hyaline. Pectoral fin with 5 or 6 irregular faint black bands across rays, pelvic fin with up to 3 black bands. Caudal fin with 4 or more black bands and a conspicuous black blotch at the middle of the caudal-fin base.

Distribution. Vanmanenia maculata is known from the Mabian-He (“He” means river in Chinese), a river discharging into the Qing-Jiang (“Jiang” means large river) of the middle Chang-Jiang basin, at Jianshi, Yidu and Changyang counties, Hubei Province, South China. It also occurs in the Li-Shui (“Shui” means river), a tributary of the Dongting Lake system (in the middle Chang-Jiang basin), at Zhangjiajie City, Hunan Province, and the Xin- Jiang, a tributary of the Poyang Lake system (in the lower Chang-Jiang basin), at Tongboshan County, Jiangxi Province ( Fig. 4 ).

Etymology. The specific epithet “ maculata ” is from the Latin word “ macula ” (stain, make spotted), referring to the presence of dark brown marks on the body.

Figures

FIGURE 2. Vanmanenia maculata, IHB 200606059, 62.8 mm SL, holotype. Dorsal view (upper), lateral view (middle), and ventral view (lower).

FIGURE 3. Mouthpart soft-tissue structures of four species of Vanmanenia: (A) V. striata: IHB 646482, 53.2 mm SL; (B) V. maculata, IHB 200606059, 62.8 mm SL, holotype; (C) V. pingchowensis, IHB 2012120233, 68.1 mm SL, and (D) V. xinyiensis, IHB 77 VII 075, 88.0 mm SL. lj: lower jaw; mb: maxillary barbel; rb: rostral barbel; rf: rostral fold; srb: secondary rostral barbel; uj: upper jaw; ul: upper lip.

FIGURE 4. Distributions of three Chinese species of Vanmanenia: V. maculata (●), V. pingchowensis (■) and V. stenosoma (▲). Closed symbols indicate localities based on materials examined. Open symbols indicate localities based on published literatures.