Claea minibarba, Zhang & Luo & Huang & Zhang, 2024

Zhang, Chu-Yi, Luo, Pan, Huang, Feng & Zhang, E., 2024, Revision of the loach genus Claea Kottelat, 2010 (Teleostei: Nemacheilidae) in China, with a description of a new species from the Chang-Jiang basin, Zootaxa 5543 (3), pp. 404-422 : 413-415

Claea minibarba sp. nov.

urn:lsid:zoobank.org:pub:7CACA96F-36D9-4715-8988-1ED68AD3D0A8

( Figures 8–9 )

Oreias dabryi : Yang et al., 1987: 156 ( China: Hubei: Changyang and Jianshi counties, in Qing-Jiang); Tang et al., 2001:14 ( China: Hubei: You-Shui, a tributary to Yuan-Jiang).

Schistura dabryi : Zhu, 1989: 55 ( China: Guizhou: Wu-Jiang in Bijie City); Yang et al., 2022: 507 ( China: Guizhou: Chishui-He and upper of Wu-Jiang).

Holotype. IHB 202204288316 , 63.7 mm SL; South China: Hubei Province: Badong County: Shennong-Xi, a stream on northern blank of upper Chang-Jiang mainstem, at Yanduhe Town (31°17’4’’N, 110°19’33’’E); collected by L. Cao, D.M. Guo, X. Gong, and C.Y. Zhang in May 2022.

Paratypes. IHB 202204288315 , 202204288317–18 , 3 specimens, 48.8–62.2 mm SL; all other data same as holotype . IHB 2017097697–99 , 3 specimens, 65.4–69.9 mm SL; South China: Hubei Province: Jianshi County: Yesan-He, a stream tributary to Qing-Jiang of middle Chang-Jiang basin , at Gaoping Town (30°35’09’’N, 110°6’52’’E); collected by L. Cao, D. M. Guo, X. Gong, and M. Wang in November 2021 .

Non-types. IHB 202204287747–49 , 3 specimens; South China: Hubei Province: Badong County: Yesan-He, a stream tributary to Qing-Jiang of middle Chang-Jiang basin , at Yesanguan Town (30°35′34″N, 110°6′17″E); collected by L. Cao, D. M. Guo, X. Gong, and C. Y. Zhang in May 2022 .

Diagnosis. Claea minibarba is distinguished from two congeneric species by having a deeper body (depth 14.7–17.6, mean 15.9, % SL vs. 9.6–15.0, mean 12.5, in C.dabryi , and 9.3–13.6, mean 12.1, in C. wulongensis ; Figure 3b ). It is further distinct from C. dabryi in having shorter outer rostral barbels extending to (vs. beyond) the anterior margin of eye, with its length 22.1–28.0 (vs. 30.2–47.5) % of HL ( Figure 3c ) and shoter maxillary barbels extending to the middle of eye (vs. beyond the posterior margin of eye), with its length 21.5–29.6 (vs. 29.8–47.4) % of HL( Figure 3d ) and from C. wulongensis in having a higher count of vertebrae (4+41–43 vs. 4+38–39), a deeper caudal-peduncle (depth 9.5–11.7% of SL vs. 7.6–9.4; Figure 3e ), and a narrower interorbital space (width 30.3– 36.3% of SL vs. 38.5–43.1; Figure 3a ). The main diagnostic characters for the new species and their congeneric species are provided in Table 4 .

Description. Morphometric measurements for type specimens summarized in Table 1 . General body appearance illustrated in Figure 8 . Body elongated, anteriorly subcylindrical and posteriorly compressed laterally, with maximum depth at dorsal-fin origin and minimum caudal-peduncle depth closer to the posterior end of anal-fin base than to caudal-fin base. Dorsal profile rises evenly from snout tip to dorsal-fin origin, then from there to dorsal origin of percurrent caudal-fin rays slightly concave. Ventral profile of head flattened, and ventral profile of preanal body straight and slightly concave from anal-fin origin to caudal-fin base.

Head slightly depressed, wider than deep. Snout blunt in lateral view and slightly pointed in dorsal view, longer than postorbital head. Anterior and posterior nostrils adjacently located; anterior nostrils in short tube, each with its tip elongated to form a short barbel; posterior nostrils not extending to anterior margin of orbit. Eyes small, and dorsolateral in middle of head; interorbital space broad, twice as wide as eye diameter, and slightly convex. Mouth inferior, moderately arched, with mouth opening reaching vertical through anterior nostril. Lips thick, slightly furrowed or smooth, but non-papillose; upper lip with slight median incision, lower lip with median interruption and several folds on each side forming median lobes. Upper jaw with median processus dentiformis ( Figure 6a ), and lower jaw scoop-shaped, with sharp cutting edge, slightly exposed outside lower lip. Three pairs of barbels; maxillary pair longer than outer rostral barbel, but not extending to posterior margin of eye; outer barbels relatively longer, reaching anterior margin of eye, and inner rostral barbels short, not extending to corner of mouth.

Fins flexible. Dorsal fin with three unbranched and eight branched rays, last unbranched ray soft and first branched ray longest, but shorter than head; distal margin truncate; origin closer to caudal-fin base than to tip of snout; tip of adpressed fin rays surpassing vertical of vent. Pectoral fin with one unbranched and 10 branched rays, inserted immediately posterior to vertical line through posterior-most margin of opercule, extending beyond midway to pelvic-fin insertion: tip of adpressed fin rays surpassing midway to pelvic-fin insertion. Pelvic fin with one unbranched and six branched rays; inserted anterior to dorsal-fin origin; tips of depressed pelvic fins not or just reaching midpoint between pelvic-fin insertion and anal-fin origin, or far from anus. Anal fin with one unbranched and five branched rays; distal margin truncate; inserted slightly posterior to midpoint between pelvic-fin insertion and caudal-fin base; tip of adpressed fin rays extending slightly beyond halfway to caudal-fin base. Caudal fin with 9+9 branched rays, moderately forked, with upper and lower lobes equal in length.

Body unscaled; lateral line complete and almost straight, extending from behind extremity of gill opening along mid-lateral body to terminate middle caudal-fin base. Stomach U-shaped; intestine short, zigzag in shape posterior to stomach. Gas bladder bipartite; anterior chamber enclosed in a dumbbell-shaped bony capsule and posterior chamber completely degenerated. Vertebrae 4+41–43 (seven specimens).

Coloration. In freshly collected individuals ( Figure 9 ), ground color of head and body yellowish, and slightly lighter ventrally. Back and lateral head peppered with dark and golden flecks, and ventral head whitish. Eight distinct brown transverse saddles across dorsum, each broader than interspaces; three saddles predorsally, two below dorsal-fin base, and three postdorsally. Indistinct irregular-shaped light brown blotches on flank, predorsally disconnected from saddles, and posteriorly fused to form a continuous piece terminating in a dark brown square marking on caudal-fin base, extending dorsally to connect with saddles on dorsum and ventrally at least to level of pectoral-fin base. One proximal and one median golden band across dorsal fin. One to three brown bands across caudal fin, and arranged regularly. Other fins peppered with black spots.

In formalin-preserved specimens ( Figure 8 ), ground color yellowish-white, lighter ventrally. Dorsal head yellowish to grayish brown; except brownish gill cover, lateral and ventral head lighter yellowish. Eight transverse dark brown saddles on back, each wider than interspaces; three saddles pre-dorsally, two below dorsal-fin base, and three post-dorsally. Irregular-shaped brownish blotches on flank, dorsally connected with saddles on back, predorsally closely set and postdorsally arranged irregularly to form a discontinuous pattern ending in a brown, oblong marking on caudal-fin base. Dorsal fin dusty with some spots on distal portion. Two indistinct W-shaped markings across caudal fin. Other fins semitransparent with yellowish basal portion.

Sexual dimorphism. No sexual dimorphism was observed in type specimens examined ( Figure 4 ).

Distribution and habitat. Known only from the Yesan-He, a stream tributary to the Qing-Jiang of the middle Chang-Jiang basin, in Badong and Jianshi counties, and the Shennong-Xi, a stream on the northern bank of the upper Chang-Jiang mainstream, in Badong County, Hubei Province, southern China ( Figure 10 ). It was previously misidentified as C. dabryi from the Qing-Jiang ( Yang 1987) and Wu-Jiang ( Zhu 1989; Tang et al. 2001). Claea minibarba was collected in clean rapid-running waters with mixed substrates including boulders, gravels, and pebbles ( Figure 11 ). Coexisting fish species are Rhynchocypris oxycephalus (Sauvage & Dabry de Thiersant) and Vanmanenia maculata Yi, Zhang & Shen.

Etymology. The specific epithet, used as a noun, is derived from the Latin word minimus (minute) and barba (beard), alluding short outer rostral and maxillary barbels. “ñḠƜDZ” is the Chinese common name here suggested for this species.

Figures

FIGURE 3. Relationship between interorbital width and head length (a); body depth and standard length(b); outer rostral-barbel length and head length (c); maxillary-barbel length and head length (d); caudal-peduncle depth and standard length (e) for Claea dabryi (blue square), C. minibarba sp. nov. (red circle), and C. wulongensis (green triangle).

FIGURE 4. Lateral view of head (a) and dorsal view of pectoral fin (b) of Claea minibarba sp. nov.: IHB 202204288316, holotype, 63.7 mm SL.

FIGURE 6. Ventral view of head for: (a)Claea minibarba sp. nov., IHB 202204288316, holotype, 63.7 mm SL and (b) C. wulongensis, SWU 2019051309, holotype, 64.0 mm SL.

FIGURE 8. Lateral (a), dorsal (b), and ventral (c) views of body in Claea minibarba sp. nov.: IHB 202204288316, holotype, 63.7 mm SL, South China: Hubei Province: Badong County: Shennong-Xi, a tributary on northern blank of upper Chang-Jiang mainstream.

FIGURE 9. Lateral view of body for a freshly captured individual of Claea minibarba sp. nov.: IHB 2017097697, paratype, 66.0 mm SL, South China: Hubei Province: Jianshi County: Yesan-He.

FIGURE 10. The main distribution basin of Claea dabryi (triangle), C. wulongensis (pentagon) and the distribution of sampling localities for C. minibarba sp. nov. (circle).

FIGURE 11. Habitat of the type locality of Claea minibarba sp. nov..