taxonID	type	description	language	source
03F987CE8D694132FF52F84031634267.taxon	vernacular_names	(New standard Japanese name: Tosa-shima-dojyô)	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	description	(Figures 3 to 9)	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	materials_examined	Holotype. BSKU 119305, 64.2 mm SL, male; Japan: Kochi Prefecture: Okuura River at Susaki, about 20 km west of Kochi, 33.4261 ºN, 133.3592 ºE, H. Takahashi, 13 Feb. 2015.	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	materials_examined	Paratypes. BSKU 131585, 61.6 mm SL, male; BSKU 137902, 74.2 mm SL, male; BSKU 137903, 64.0 mm SL, male; same data as holotype. — BSKU 119304, 92.2 mm SL, male; BSKU 137901, 92.2 mm SL, male; same place as holotype; H. Takahashi, 11 Feb. 2015. — BSKU 119303, 82.2 mm SL, male; Sakanokawagawa River in Shinjyô drainage, at Susaki City about 26 km west of Kochi, 33.395 ºN, 133.2659 ºE; H. Takahashi, 16 April 2015. — TKPM-P 27320, 67.2 mm SL; male, Wajiki River at Geisei about 30 km east of Kochi, 33.5381 ºN, 133.8113 ºE, H. Takahashi, 16 Jan. 2015. BSKU 119313, 78.4 mm SL; same data as TKPM-P 27320, male; same place as TKPM-P 27320, H. Takahashi, 11 Feb. 2015; TKPM-P 27321, 66.8 mm SL, male; Agricultural canal flowing into Monobe River at Konan City about 20 km east of Kochi City, 33.5691 ºN, 133.6873 ºE, hand net, coll. H. Takahashi, 1 May 2015; TKPM-P 27322, 77.7 mm SL, male; Yamakita River in Kôsô River System at Konan City about 24 km east of Kochi City 33.5718 ºN, 133.7486 ºE, hand net, coll. H. Takahashi, 30 January 2016; TKPM-P 27324, 76.2 mm SL; female, same data as BSKU 119303; TKPM-P 27325, 69.4 mm SL, female; same data as BSKU 119303; BSKU 119312, 85.2 mm SL, female; same data as BSKU 27320; TKPM-P 27323, 81.2 mm SL, female; same data as BSKU 27320; BSKU 119307, 81.6 mm SL, female; same data as TKPM-P 27322; BSKU 122695, 83.2 mm SL, female; Yasu River at Konan City about 26 km east of Kochi City 33.5496 ºN, 133.7731 ºE, hand net, coll. H. Takahashi, 9 April 2016; BSKU 137905, 76.2 mm SL; same data as BSKU 122695; BSKU 122720, 89.3 mm SL; Shinjyô River at Susaki City about 26 km west of Kochi City, 33.3917 ºN, 133.2628 ºE, hand net, coll. H. Takahashi, 31 August 2001; BSKU 122873, 76.7 mm SL, female; Aki River at Aki City about 40 km west of Kochi City 33.5373 ºN, 133.9053 ºE, hand net, coll. H. Takahashi.	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	diagnosis	Diagnosis Cobitis tosaensis is distinguished from C. biwae by the following combination of characters: Suborbital spine with three pointed ends (vs. two) — first on anterior tip, second at about 1 / 3 of outer margin from tip, and third at about 1 / 2 of outer margin from tip, lamina circularis kitchen-knife shaped (vs. beak-shaped), with neck about 1 / 3 from base of posterior margin (vs. curved and protruding, connecting to narrow tip section). In adults, Z 2 almost thick as eye diameter in many individuals (vs. slimmer than eye diameter), two black spots on surface layers of caudal-fin base, both usually separated from upper and lower (vs. two broad patterns: upper black spot distinct and lower indistinct; and single rod-shaped black spot), two light greyish spots on deeper layer of caudal-fin base, both separated from upper and lower (vs. thin, light greyish elliptical spot arranged vertically, with spaces between them connected).	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	description	Description. See figures 3 – 4 and 8 – 9 for general appearance, and table 1 for morphometric data of the holotype and 20 paratypes (10 males and 10 females). Body elongated, laterally compressed. Head moderately large, snout short. Interorbital space narrow. Eyes moderately small, situated above centre of head (Figure 5 A). Caudal peduncle compressed, its depth 0.58 – 0.92 times its length. Mouth small, with fleshy lips. Lower lip divided with two welldeveloped lobes (Figure 5 B). Upper lip with transverse wrinkles on surface. Barbels well developed; first on rostrum, second on maxilla, and third on mandible (Figure 5 A, B) — second barbel longest, reaching 13.9 – 30.3 % of head length. Nostrils nearer to eye than tip of snout, close together; anterior nostril on top of a short tube (Figure 5 A). Suborbital spine with three pointed ends — first on anterior tip, second at about 1 / 3 of outer margin from tip, and third at about 1 / 2 of outer margin from tip (Figure 6 A). Scales on trunk minute, cycloid. Pectoral fin elongated, first branched soft ray longer, broad than others (Figure 5 C). Lamina circularis at pectoral-fin base in adult male kitchen-knife shaped, strongly overhanging near base, angulated at outer margin; posterior margin of joint strongly constricted; ratio of two lengths from distal tip to neck and neck to base approximately 1: 1.3 (Figure 7 A, C). Dorsal fin with 3 unbranched and 6 ½ (19), 7 ½ (2) branched rays; anal-fin with 3 unbranched and 4 ½ branched rays; caudal-fin with 9 + 9 branched rays; pectoral-fin with 7 (2), 8 (19) branched rays; pelvic-fin with 5 (1), 6 (20) branched rays; 15 prepelvic myotomes. Colouration: In life, body transparent milky white, with a yellowish tinge on dorsal surface of trunk from rostral tip to caudal-fin base (Figure 8). Abdomen from back to upper part of body pale orange in both sexes during spawning season, sometimes yellowish in spawning females (Figure 9). Dark brown oblique band running from rostrum to eye. Z 1 — dark brown band extending from rear end of head to base of caudal fin, above which are 4 to 6 dark, square blotches between posterior end of head and dorsal-fin base and 4 to 7 between posterior end of dorsal- and caudal-fin base, and surrounded by narrow, worm-eaten dark brown freckles or cloud-like freckles. Z 2 — dark brown and distinct. Longitudinal band or wavy line around dorsal fin, dotted from just below beginning of dorsal fin to caudal-fin base. In adults, Z 2 almost thick as eye diameter in many individuals. In juveniles, thickness of Z 2 is less than eye diameter from rear of head to base of dorsal fin, but exceeds eye diameter beneath and behind dorsal fin. Z 3 — indistinct, without spots, or with a few pupil-sized, dark brown spots around posterior edge of opercle. Z 4 — 8 to 14 dark brown, distinct elliptical blotches distributed across central part of body. Only the most forward blotch becomes a horizontal bar-shaped object. Longitudinal band on deep skin layer in middle of body dark purple to blue. Abdomen without spots. Ground colour of each fin milky white; distinct black spots on stripes of dorsal and caudal fins, forming striped patterns of 3 or 4 rows. Pectoral, ventral, and anal fins usually unspotted. Spots on caudal fin-base divided into surface and deep layers (Figure 4 A, E): upper spot on surface layer oblong, dark black, distinct; lower spot oblong or jellybean-shaped, slightly paler and brownish brown. In most specimens, upper and lower spots separated from each other (Figure 4 A); upper spot in deep layer oblong, lower one drop-shaped or ricegrain-like. In all specimens, upper and lower spots separated from each other (Figure 4 E).	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	etymology	Etymology. The species name is derived Tosa — the old name of Kochi Prefecture, to which the species is endemic to.	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	distribution	Distribution. This species is distributed from rivers flowing into Tosa Bay, including the Ioki River in the east and the Shinjô River in the west (Figure 10).	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	biology_ecology	Ecology. The new species is found mainly on sand and gravel bottoms in the middle reaches of rivers, where it feeds on aquatic insects and detritus. Cases of spawning upstream in agricultural canals flowing into rivers in April and May have been reported (Takahashi and Nagae, 2020), while spawning behaviour and early development in captivity has been studied by Nagae et al., (2021).	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
03F987CE8D694132FF52F84031634267.taxon	discussion	Remarks. In addition to this new species, two other species within the ‘ C. biwae species complex’ sensu Nakajima et al., (2012) exist, that require new names and description as separate species. One of these is Cobitis biwae C, distributed across Honshu from the Tohoku region to the Tokai region. The other is the Cobitis biwae B, distributed across the Tokai, Kinki and San’in regions. In addition, detailed research is also required on the identity of populations inhabiting parts of the Tokai region, where the distributions of both ‘ putative species’ overlap.	en	Takahashi, Hiroaki (2026): A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae). Zootaxa 5768 (3): 381-391, DOI: 10.11646/zootaxa.5768.3.4, URL: https://doi.org/10.11646/zootaxa.5768.3.4
