Cobitis laterstriata Li & Zhao 2026, sp. nov.

Cobitis laterstriata Li & Zhao sp. nov. Figs 2, 3, 4, 5, Table 2 Type material. Holotype. • ASIZB 254919, 71.7 mm SL; Wanjia Township, Ningguo City, Anhui Province, from a tributary of the Shuiyangjiang River, which is a tributary of the Yangtze River (30.4045°N, 119.1441°E, 130 m a. s. l.); collected by Haojun Chen; August 21, 2025. Paratypes. 47 specimens • ASIZB 254918, 254920, 254934–254962, 254970–254985, 40.8–74.3 mm SL; same collection information as holotype. Diagnosis. The new species can be distinguished by the following combination of characters: no Gambetta pattern; dorsal blotches barely extend to lateral side; upper lateral side covered with dense, irregular cloud-shaped blotches; a blank zone above mid-lateral line ventral to these blotches; a well-defined black mid-lateral stripe extending from posterior edge of operculum to caudal-fin base, with 10–15 irregular black blotches scattered directly ventrally; lower lip and mandible separated, with well-developed mental lobes; caudal peduncle short; 19–20 pre-pelvic myotomes; dorsal fin with six branched rays; anal fin with four branched rays. Description. Body medium-sized, elongated, slightly compressed laterally. Body width and depth tapering gently posterior to dorsal fin toward caudal-fin base. Head ventral surface flattened; abdomen slightly rounded; dorsal body profile smoothly ascending snout-occiput; occiput to caudal-fin base nearly horizontal. Caudal peduncle short, laterally compressed, with developed fleshy keels on dorsal and ventral side. Head short, small, laterally compressed. Snout bluntly rounded (lateral view), sharply triangular (dorsal view); snout length subequal to postorbital length. Eye small, superior and laterally positioned, with convex and narrow interorbital space. Anterior and posterior nostrils closely situated; anterior nostril with short tube. Anus located immediately anterior to anal-fin insertion (Figs 2, 3, Table 2). Mouth small, inferior. Three pairs of short barbels: one pair of rostral barbels not reaching mouth corners; one pair of maxillary barbels not reaching under anterior edge of orbit; one pair of maxillomandibular barbels shorter than or almost equal to eye diameter. Lips fleshy, smooth; upper lip broad, without affiliated apparatus; lower lip short, separated from mandible, divided into two well-developed mental lobes (Fig. 3). Head scaleless. Body covered with small, round or oval scales. Each scale has a large eccentric focal area (being closer to base), with 14–24 radial grooves, and one to five supplementary radial grooves (radial grooves broad, sparse anteriorly, dense basally) (Fig. 4). Lateral line short, not reaching to tip of pectoral fin. Pre-pelvic myotomes 19 or 20 (Table 2). Dorsal fin short, with three unbranched and six branched rays, located in posterior half of body; distal margin slightly convex. Pectoral fins short, with one unbranched and seven branched rays. Pelvic fins with one unbranched and six branched rays, inserted below second or third branched dorsal-fin ray. Anal fin short and small, with three unbranched and four branched rays, inserted nearer to caudal-fin base than to pelvic-fin insertion. Caudal fin slightly truncated, with one unbranched principal ray and seven branched principal rays on upper part and seven branched principal rays and one unbranched principal ray on lower part. (Fig. 2, Table 2). Total vertebrae 4 + 42 (4 specimens), 43 (2), 44 (2) (Table 2). Suborbital spine thick and curved; tip reaching middle of orbit (Fig. 5). Coloration in live specimens. Dorsal and lateral surfaces of head and body light brownish-yellow; ventral surface grayish white; operculum with slight iridescence. A distinct dark black stripe extends from insertion of first rostral barbel, passing through eye, to occiput. Numerous dense black spots on head, sometimes forming several black stripes under eye. No Gambetta pattern. A conspicuous black stripe along dorsal midline, extending from occiput, passing through dorsal fin, to caudal-fin base, with 14–19 uniformly spaced, small, short black blotches embedded in stripe, which barely extend to lateral side; irregular, dense, cloud-like black plaques on upper lateral side (smaller, denser post-head; larger, scattered toward caudal peduncle); a blank zone above mid-lateral line ventral to these blotches; almost devoid of blotches. A prominent, dark black fine stripe along mid-lateral line, extending from posterior margin of operculum to caudal-fin base; 10–15 irregular black blotches closely arranged ventral to mid-lateral line (oblong-oval anteriorly, vertically elongated posteriorly); sometimes coalescing into a broad black stripe in anterior body which may be sex-related. All fins hyaline and whitish; except pectoral and pelvic-fins base pale light orange. Three to four rows of black spots present on dorsal and caudal-fin rays; few black spots on distal part of pectoral fin and base of pelvic fin and anal fin. A distinct, jet-black large spot on upper caudal-fin base; a smaller, paler spot sometimes present ventrally to it (Fig. 10). Coloration in preserved specimens. Dorsal and lateral surfaces of head and body light yellow; ventral surface pale; operculum without slight iridescence. All patterns in same position as living specimen (Fig. 2). Sexual dimorphism. Not obvious in external morphology. Distribution and habitat. Cobitis laterstriata sp. nov. is distributed in tributaries of the Shuiyangjiang River (a tributary of the Yangtze River) in Wanjia and Nanji Township, Ningguo City, Anhui Province. This species is also found in the Tianmuxi River (a tributary of the Changhuaxi River) in Zhangjia Village, Chakou Township, Lin’an District, Hangzhou City, Zhejiang Province. This species typically inhabits shallow rivers with gravel bottoms (Figs 1, 6). Etymology. This specific name derives from the Latin later, meaning alongside of body, and Latin striata meaning stripes or bands, in reference to the prominent, dark black stripe that runs along the mid-lateral line from the posterior edge of the operculum to the caudal-fin base. The Chinese name suggested for this species is “侧带花鳅”. Morphological comparison Based on morphological measurement data, our study conducted a principal component analysis (PCA) to understand the potential morphological differences among Cobitis laterstriata, C. xinjiangensis and C. nigrolinea. Among these, C. xinjiangensis is the most morphologically similar to C. laterstriata, while C. nigrolinea shows the closest geographic proximity. The analysis incorporated 24 morphometric measurements from 48 individuals of C. laterstriata, 18 of C. nigrolinea and 16 of C. xinjiangensis. Results revealed that, in terms of morphology, C. laterstriata is significantly different from those of the other two species. The first three components contributed a total of 87.39 % of the variance. Principal component 1 (PC 1) represents most of the body size of the specimens, while PC 2 and PC 3 represents shape-related morphological traits. The PCA loadings are presented in Table 3, showing that interorbital width, fin base length, caudal peduncle length and distance between pectoral - fin and pelvic-fin insertion contribute most to PC 2 and PC 3. In conclusion, both PC 1 against PC 2 and PC 2 against PC 3 are able to separate C. laterstriata from the other three Cobitis species (Fig. 7). Molecular phylogeny and genetic comparisons A total of 38 sequences from 15 Cobitis species were included in the analyses. Among these, a total of 19 new Cytb sequences were obtained through our field surveys, including nine Cytb sequences of new species, two sequences of C. brevipinna, two sequences of C. nigrolinea, four sequences of C. xinjiangensis, one sequence of C. zhejiangensis Son & He, 2005 and one sequence of C. dolichorhynchus Nichols, 1918. Additional sequences downloaded from NCBI including two Cytb sequences from C. brevipinna, one sequence from C. laterimaculata, two sequences from C. fimbriata, one sequence from C. nigrolinea, three sequences from C. qujiangensis, one sequence from C. tigrina, two sequences from C. longibarba, one sequence from C. xinjiangensis, three sequences from C. delicata Niwa, 1937, one sequence from C. crassicauda Chen & Chen, 2013, one sequence from C. fasciola Chen & Chen, 2013 and one sequence from C. stenocauda Chen & Chen, 2013. One sequence from Sabanejewia aurata was designated as the outgroup. The molecular phylogenetic results (BI and ML trees in Figs 8, 9) based on mitochondrial Cytb sequences show that nine samples of the newly described species form a monophyletic group itself, which is a sister group to C. fimbriata. These samples were also closely related to those of other Chinese Cobitis species, which collectively formed a well-defined clade. The interspecific genetic distance between C. laterstriata and C. fimbriata is 3.55 %. The intraspecific genetic distances in C. laterstriata, C. fimbriata, C. nigrolinea, C. qujiangensis, C. longibarba, C. brevipinna, C. xinjiangensis and C. delicata are 0.69 %, 0.88 %, 0.65 %, 0.47 %, 0.09 %, 1.16 %, 1.09 % and 0.65 %, respectively (Table 4), which are much lower than the interspecific genetic distances. In conclusion, the molecular phylogenetic results support C. laterstriata as a distinct species.