Sineuchiloglanis baishuiensis Lv, He, Lei & Liu, 2026, sp. nov.

Sineuchiloglanis baishuiensis sp. nov. Figs 6, 7 Type material. Holotype • IHB 202507042, 94.47 mm SL; Baishui River in the upper Yangtze River drainage in Zhenxiong County, Yunnan Province, China (27°38N, 104°46E; 791 m elevation); August 2024, Liu F. Paratypes • IHB 202507023 –202507039, 17, 74.61–178.80 mm SL; Baishui River in the upper Yangtze River drainage in Zhenxiong County, Yunnan Province, China; April 2024, Liu. F. • IHB 202507040, 202507041, 202507043, 202507044, 4, 76.16–146.29 mm SL; Baishui River in the upper Yangtze River drainage in Zhenxiong County, Yunnan Province, China; August 2024, Liu. F. • IHB 202507047, 1, 205 mm SL; Waqiao River (a tributary of the Baishui River in the upper Yangtze River drainage) in Zhenxiong County, Yunnan Province, China; May 2025, Liu. F. • IHB 202507048, 1, 60 mm SL; Waqiao River (a tributary of the Baishui River in the upper Yangtze River drainage) in Zhenxiong County, Yunnan Province, China; August 2022, Liu. F. Diagnosis. Sineuchiloglanis baishuiensis sp. nov. can be readily distinguished from congeners by the following characters: dorsal-fin rays i, 5 1 / 2; anal-fin rays i, 4 1 / 2; caudal-fin rays i, 7 + 8, i; gill opening extending to the base of fourth to fifth pectoral-fin elements; tip of maxillary barbel not reaching the lower corner of the gill opening; tip of nasal barbel not reaching anterior orbital margin; the ventral abdominal surface flattened (Fig. 4). And it can be further distinguished from congener by the following characters: head length behind the eyes 35.4–39.4 % of HL; head depth 42–48.4 % of HL; maxillary barbel length 65.9–82.1 % of HL; pelvic insertion to adipose origin 17.3–22.3 % of SL; dorsal-fin insertion to adipose-fin origin length 15.5–25.5 % of SL; caudal-peduncle length 20.6–26.7 % of SL; head width 18.1–21.0 % of SL; post-adipose length 8.1–11.2 % of SL; pectoral-fin width 61.0–78.2 % of pectoral-fin length; pelvic-fin width 53.6–76.6 % of pelvic-fin length; caudal-peduncle depth 25.9–40.6 % of caudal-peduncle length. The primary diagnostic characters for species of Sineuchiloglanis are summarized in Table 2. Description. Morphometric characters of 22 type specimens are shown in Table 3. Dorsal-fin rays i, 5 1 / 2; pectoral-fin rays i, 12–14; pelvic-fin rays i, 5; anal-fin rays i, 4 1 / 2; caudal-fin rays i, 7 + 8, i; vertebra 13 + 23 = 36 (n = 2); 13 + 24 = 37 (n = 2). (Table 4). Body compressed, with a slightly raised back. Depth of body is 11.5–17.4 % of SL, width of body is 14.3–17.3 % of SL. Head depressed, rostral margin rounded when viewed dorsally. Depth of head is 8.7–11.4 %, width of head is 18.1–21.4 % of standard length. Body smooth and scaleless, lateral line complete and midlateral. Oral region and anterior part of abdomen with dense papillae, density gradually decreasing posteriorly. The ventral abdominal surface is flattened. Caudal fin truncate, with two unbranched and 7 + 8 branched fin rays (Fig. 7). Dorsal-fin located in anterior third of body, with two unbranched and six branched fin rays (the last branched fin ray branches from the base of anal-fin), without spine, outer margin straight; tip of dorsal-fin rays extending beyond vertical through pelvic-fin base when depressed. Adipose fin located in anterior three-fifths of body, not confluent with caudal fin. Pectoral-fin enlarged, located in anterior one-fifth of body, with one unbranched and 13 branched fin rays; first element on each broadened; regular striae on ventral surface; tip of pectoral-fin rays reaching or not reaching pelvic-fin origin. Pelvic-fin enlarged, located in anterior two-fifths of body, with one unbranched and five branched fin rays; first ray of each broadened; regular striae on ventral surface; tip of pelvic-fin rays not reaching, reaching, or extending beyond anus. Anal-fin located in anterior two-thirds of body, with one unbranched and five branched fin rays (last branched fin ray branches from the base of anal fin). Anus is located approximately at midpoint of the distance between the pelvic-fin insertion and the anal-fin origin, close to the pelvic-fin insertion. Mouth wide (mouth width of 33.0–40.4 % of HL), inferior, transverse. Premaxillary tooth band with a deep median indentation, sides not extending posteriorly. Dentary tooth band with two short, wide patches. Oral teeth conical, pointed. Barbels four pairs. Maxillary barbel with flap of skin fringing posterior margin, tip pointed, not reaching the lower corner of gill opening. Lower lip connected to base of maxillary barbel by skin flap, without sulcus between them. Mandibular barbels two pairs, inner mandibular barbel shorter than outer mandibular barbel. Origin of inner mandibular barbel close to midline. Outer mandibular barbel originating posterolateral of inner mandibular barbel. Post-labial groove interrupted, ending at base of inner mandibular barbel. Nasal barbel with small flap of thin skin fringing posterior margin, not reaching anterior margin of orbital. Eye small, almost round, subcutaneous, located on upper lateral surface of head, closer to dorsal-most extremity of gill opening. Gill opening extending to the base of fourth or fifth pectoral-fin elements. Coloration. In fresh species, body green-yellow on dorsal surface. On venter, from snout to the pelvic-fin insertion milky white, after pelvic-fin green-yellow. Around the anus pale yellow. Pectoral-fin and pelvic-fin with pale yellow distal margins, lateral green-yellow and medial pale yellow. Dorsal fin, adipose fin, and anal fin green-yellow with pale yellow distal margins. Caudal fin green-yellow with a small pale yellow patch and pale yellow distal margin. In alcohol-fixed specimens, body grey, ventral surface, and margins of fins milky white. Ecology and habitat. Sineuchiloglanis baishuiensis sp. nov. inhabits rapids and riffles, with primarily rocky substrates. (Fig. 8) The water temperature was 19.9 ° C during the survey period in August 2024. The species co-occurred with Schizothorax grahami in this type locality. Distribution. This new species is currently known only from the Baishui River in the Yangtze River drainage, in Zhenxiong County, Yunnan Province, China. Etymology. The specific epithet is derived from its type locality, Baishui River.