Beaufortia zebroida ( Fang 1930 ), 2012

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 zebroida ( Fang 1930)

Fig. 15

Gastromyzon pingi zebroidus Fang, 1930: 35 (original description: Donggui River, Longzhou County, Guangxi).

Beaufortia zebroidus : Hora (1932): 319.

Gastromyzon pingi zebroidus : Nichols (1943): 231.

Beaufortia pingi : Nguyen and Nguyen (2005): 282–283

Beaufortia fasciolata Nguyen & Nguyen, 2005: 588–590.

Beaufortia multiocellata Nguyen & Nguyen, 2005: 590–592.

Beaufortia triocellata Nguyen & Nguyen, 2005: 592–594.

Beaufortia zebroida : Kottelat (2012): 59–60.

Comparative materials.

MMNHN 1544, one specimen, holotype, not found yet, refers to the original description. SHOU 20240111301-317, 33.24–49.96 mm SL, 17 specimens from Guangnan County, Xichou County, Malipo County, Funing County, Yunnan, and Napo County, Guangxi, SHOU 20240111301-317, 33.24–49.96 mm SL, were collected by Lao Xing and Lin Yang from December 2021 to January 2024.

Diagnosis.

B. zebroida shares the typical characteristics with members of the B. pingi species group, with distinct vertical stripes on lateral body 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 B , 7 , Table 2 ). B. zebroida can be clearly distinguished from B. granulopinna sp. nov. by the absence of prominent tubercles on the pectoral fin rays (vs. well-developed tubercles present on anterior 6–9 rays of pectoral fins); vertical stripes slender, narrower than inter-spacing, present consistently at all growth stages (vs. vertical stripes typically wider than inter-spacing, with a certain proportion (54.76 %) of adults exhibiting blurred or vanished mid-section stripes). B. zebroida can be clearly distinguished from B. viridis sp. nov. by the vertical stripes present uneven in width and length, typically narrower than inter-spacing, sometimes reduced to dots (vs. stripes of consistent length, width, and inter-spacing); body brown yellow to golden in dorsal profile (vs. dark cyan to green). B. zebroida can be clearly distinguished from B. pingi by the stable presence of vertical stripes at all growth stages (vs. a large proportion (94.00 %) of adults with blurred or vanished vertical stripes at mid-section of lateral body) and body brown yellow to golden in dorsal profile (vs. dark brown to green).

Redescription.

Dorsal iii- 7; anal ii- 3–4 (3.98 ± 0.14); pectoral i- 20–23 (21.5 ± 0.73); pelvic i- 16–19 (17.53 ± 0.86). Lateral-line canal pores and scales: 70–84 (75.12 ± 3.55).

Morphometric measurements for the specimens examined are given in Table 3 . See Fig. 15 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.

Coloration in preservation.

Preserved specimens from sub-adult to adult stage, body brown yellow 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 with 8–15 vertical dark stripes, varying greatly in length, which sometimes appearing as dots, stripe width narrower than inter-spacing, present at all growth stages. 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 second branched ray.

Coloration in live.

In life, body brown yellow to golden in dorsal profile. Mature individuals with a more vivid golden coloration, and fin membranes pale yellow.

Individual variation.

Among 17 specimens, one ( SHOU 20240111307) had three branched anal fin 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.

Distribution.

Exclusively in small tributaries on the north bank of the mid-lower Red River system and the upper Shuikou River to Zuo River basin (upper Pearl River system), from Maguan County, Wenshan Zhuang, and Miao Autonomous Prefecture, Yunnan, to Longzhou County, Guangxi, near the China-Vietnam border, extending into northeastern Vietnam (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 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 15. Lateral (top), dorsal (middle), and ventral (bottom) views of different regional phenotypes of Beaufortia zebroida. А. Regional phenotype from a stream tributary to the Red River, Guangnan County, Yunnan, SHOU 20240111308, 36.64 mm SL; B. Regional phenotype from Napo County, Guangxi, SHOU 20240316602, 56.12 mm SL, originating from upstream within the same basin as the type locality.