Beaufortia pingi ( Fang 1930 )

Chen, Jing-Chen, Li, Jia-Jia, Tang, Wen-Qiao, Pu, Xin-Rui & Lei, Hao-Tian, 2024, Taxonomic resolution of the hillstream suck-loach Beaufortia pingi species group (Cypriniformes, Gastromyzontidae) and two new species from Southwest China – Beaufortia granulopinna and Beaufortia viridis, Zoosystematics and Evolution 100 (3), pp. 941-963 : 941-963

Beaufortia pingi ( Fang 1930)

Fig. 14

Gastromyzon pingi Fang, 1930: 31–34 (original description: former Lingyun County, near the border of Yunnan and Guangxi; Damaoping Village, Lingyun County, Guangxi). Nichols (1943): 231.

Beaufortia pingi : Hora (1932): 319.

Gastromyzon pingi : Nichols (1943): 231.

Beaufortia pingi : Chen (1980): 113–114 (Xi River, Guangxi).

Comparative materials.

23 specimens from type locality, SHOU 20240102201-217, SHOU 20240126201-206, 27.64–56.89 mm SL, were collected by Qian-Yu Liang and Jing-Chen Chen from December 2022 to January 2024; 15 specimens from Youjiang District, Baise City, Guangxi Province, China, SHOU 20240110201-204, SHOU 20240127201-211, 43.53–56.28 mm SL, were collected by Qian-Yu Liang and Jing-Chen Chen from December 2021 to January 2024; 12 specimens from Debao County, Baise City, Guangxi Province, China, SHOU 20240112201-202, SHOU 20240103201-210, 44.53–58.12 mm SL, were collected by Qian-Yu Liang from April 2023 to January 2024.

Diagnosis.

B. pingi shares the typical characteristics with members of the B. pingi species group, with distinct vertical stripes on the flank and a pinnate-type lower lip (vs. lacking prominent vertical stripes and having a dicot-type lower lip in other congeneric species apart from this group) (see Figs 6 A , 7 , Table 2 ). B. pingi can be clearly distinguished from B. granulopinna sp. nov. by absent or inconspicuous tubercles on pectoral fin rays (vs. well-developed tubercles present on anterior 6–9 rays of pectoral fins); paired fins with more branched rays, with 21–24 (mean 22.19 ± 0.78) in pectoral fins and 17–21 (mean 18.64 ± 0.97) in pelvic fins (vs. 18.5–22 (mean 20.11 ± 0.77) and 15–18 (mean 16.51 ± 0.86 )). B. pingi can be clearly distinguished from B. viridis sp. nov. by vertical stripes uneven in length and width and a significant proportion (94.00 %) of adults displaying blurred or vanished stripes on the mid-section flank (vs. the stable presence of uniform vertical stripes in length, width, and inter-spacing at all growth stages). B. pingi differs from B. zebroida by having a larger proportion of adults with blurred or vanished mid-section vertical stripes (vs. stable presence of vertical stripes) and body dark brown to green in dorsal profile (vs. brown yellow to golden).

Redescription.

Dorsal iii- 7–8 (7.08 ± 0.27), anal ii- 3–4 (3.98 ± 0.14); pectoral i- 21–24 (22.19 ± 0.78); pelvic i- 17–21 (18.64 ± 0.97). Lateral-line canal pores and scales: 68–92 (75.28 ± 4.01).

Morphometric measurements for the specimens examined are given in Table 3 . See Fig. 14 for lateral, dorsal, and ventral views of the body.

Body closely resembles B. viridis sp. nov. in general shape and structure but significantly different in stripes pattern and coloration. Tubercles on rays absent or poor developed, only faintly visible in large males.

Coloration in preservation.

Preserved specimens from sub-adult to adult stage, body dark brown to grey, white ventrally. Head with black spots or vermiculation dorsally, 2–5 larger black blotches along mid-dorsal body anterior to dorsal fin. Sides of body with 4–15 vertical dark stripes, length and width of stripes uneven. In smaller individuals, stripes clear and distinguishable, in larger individuals, a significant proportion possesses a blur region before caudal peduncle, extending to dorsal fin origin at maximum, caudal peduncle with 2–5 distinct vertical stripes. Paired fin margins hyaline or pale white, inner edges with continuous or dotted black arc. Dorsal fin hyaline, with black stripes, one black spot on the root before the first branched ray.

Coloration in live.

In life, dorsal body dark brown to green. Mature individuals with metallic green longitudinal band along lateral line, area below lateral line behind pelvic fins and base of paired fins sometimes light orange, fin membranes pale green.

Sexual dimorphism.

In fully mature individuals, males slightly larger than females, with well-developed nuptial tubercles (see Fig. 8 C, D ).

Geographic variation.

Compared to type locality, Lingyun County, Guangxi, population in Debao County, Guangxi with more compressed body, and more elongated tail (see Fig. 14 B , Table 4 ).

Individual variation.

Among 50 specimens, four ( SHOU 20240102213, SHOU 20240102215, SHOU 20240126205, and SHOU 20240127211) with eight dorsal fin-branched rays; one ( SHOU 20240127204) with three anal fin-branched rays.

Ethology.

Inhabits shallow streams with rapid currents and smooth pebble substrates that adhere to crevices between stones. Feeds on algae and small invertebrates and consumes mucus from fresh fish carcasses. Exhibits territorial behavior and aggression; adults may head-butt and extend dorsal fins to drive away rivals.

Distribution.

Found exclusively in the small tributaries of the Chengbi River and Jian River to the You River basin, upper reaches of the Pearl River system, Western Guangxi, China (see Fig. 9 ).

Figures

Figure 6. Pinnate-type lower lip of the Beaufortia pingi species group, elongated, with the lower lip on both sides being multilobed, typically comprising more than three lobes, with deep divisions; the extremities of the lower lip extend to the corners of the mouth, with several wart-like protrusions present on the extended parts. The red line outlines the left side of the lower lip contour; the red arrow indicates the position of the ventral head sensory canal-pores located anterior to the origin of the pectoral fins. А. B. pingi, from the type locality; B. B. zebroida, from Napo County, Guangxi Province; C. B. viridis, from the type locality; D. B. granulopinna, from the type locality.

Figure 7. Dicot-type lower lip of species outside the Beaufortia pingi group, shorter, with the sides of the lower lip being smooth or featuring 1–2 shallow notches; the ends of the lower lip do not extend to the corners of the mouth, or the extension is poor-developed and lacks protrusions. The red line outlines the left side of the lower lip contour; the red arrow indicates the position of the ventral head sensory canal-pores, with the second pair of canal-pores located posterior to the origin of the pectoral fins in all species except B. liui. А. B. leveretti, from the type locality; B. B. kweichowensis, from Congjiang County, Guizhou Province, downstream near the type locality; C. B. cyclica, holotype; D. B. intermedia, paratype; E. B. polylepis, syntype; F. B. huangguoshuensis, syntype; G. B. szechuanensis, from Neijiang City, Sichuan Province; H. B. niulanensis, from the type locality; I. B. liui, syntype. (C-F and I were photographed by Yi-Yang Xu, Institute of Hydrobiology, Chinese Academy of Sciences.)

Figure 8. Sexual dimorphism within the Beaufortia pingi species group, with males exhibiting well-developed and numerous nuptial tubercles on the head compared to females. A, B. B. viridis sp. nov.; C, D. B. pingi; and E, F. B. granulopinna sp. nov.

Figure 9. Distribution map of species within the Beaufortia pingi species group. Light red: B. granulopinna sp. nov.; light green: B. viridis sp. nov.; light blue: B. pingi; light yellow: B. zebroida. Rivers are labeled with their names in Chinese: Qingshui River (清水江), Nanpan River (南盘江), Beipan River (北盘江), Hongshui River (红水河), Tuoniang (驮娘江), Xiyang River (西洋江), Leli River (乐里河), Chengbi River (澄碧河), Bo’ai River (剥隘河), Jian River (鉴河), You River (右江), Wuming River (武鸣河), Yu River (郁江), Shuikou River (水口河, known as Sông B ằng in Vietnamese), and Red River (红河).

Figure 14. Lateral (top), dorsal (middle), and ventral (bottom) views of different regional phenotypes of Beaufortia pingi. А. Regional phenotype from Lingyun County, Guangxi, SHOU 20240126202, from type locality, 56.89 mm SL. B. Regional phenotype from Debao County, Guangxi, SHOU 20240103203, 58.12 mm SL (left), with clearer vertical stripes; SHOU 20240103204, 53.18 mm SL (right), with blurred vertical stripes.