Barbatula linjiangensis, Chen & Zhang & Chen & Freyhof, 2019

Chen, Hao, Zhang, Hui, Chen, Yongxia & Freyhof, Jörg, 2019, A review of the Barbatula loaches (Teleostei: Nemacheilidae) from north-eastern China, with the description of four new species, Zootaxa 4565 (1), pp. 1-36 : 25-27

Barbatula linjiangensis , new species

( Fig. 26–28 )

Holotype. HU 1608016, 81.0 mm SL; China: Jilin prov.: Yalu River south-west of Linjiang City, 41°79′N 126°89′E (16); Hao Chen , Oct. 2016.

Paratypes. HU 1608014, 1608016, 1608019–20, 4, 52.3–81.9 mm SL; same data as holotype .

Additional material examined. HU 1609206, 1609242, 1609232, 1609238, 1609236, 1609239, 1708144–45, 8, 83.8–127.8 mm SL; FSJF 4049, 2, 107.7– 109.8 mm SL; China: Liaoning prov.: Pushi River at Xudianzi of Dandong Kuandian Manchu Autonomous, Yalu River drainage, 40°68′N 124°73′E (14); Hao Chen, May 2017. — — HU 1608734, 1608608, 1608609, 1608904, 4, 76.3–79.2 mm SL; China: Liaoning prov.: Ai River south of Yanjiacun in Fengcheng City, Yalu River drainage, 40°53′N 124°21′E (13); Hao Chen, May 2017 .

Material used in the molecular genetic analysis. HU 1608014, 1608016; China: Jilin prov.: Yalu River, 41°79′N 126°89′E (16). (GenBank accession numbers: MF770525 –26).— HU 1609232; China: Liaoning prov.: Pushi River, Yalu River drainage, 40°68′N 124°73′E (14). (GenBank accession number: MF 770527 ) .— HU 1608734; China: Liaoning prov.: Ai River, Yalu River drainage, 40°53′N 124°21′E (13). (GenBank accession number: MF 770528 ) .

Diagnosis. Barbatula linjiangensis is distinguished from the other species of Barbatula in north-eastern China by a combination of characters, none of them unique. It is distinguished from all other species except B. nuda and B. emuensis , by having the nostrils closely set (vs. widely spaced) and no lateral expansion of the lower lip (vs. having).

Barbatula linjiangensis is distinguished from B. nuda by having a shallow median incision in the upper lip, its depth is 10–30% of the width of the upper-lip (vs. deep, 40–60%) and sparsely set scales on flank anterior to dorsal-fin origin (vs. scales restricted to flank behind dorsal-fin base).

Barbatula linjiangensis is distinguished from B. emuensis by the snout length being equal to the postorbitalhead length (vs. shorter), having a shallow median incision in the upper lip, its depth is 10–30% of the width of the upper-lip (vs. deep, 40–60%) and the pelvic-fin origin situated below the vertical through the dorsal-fin origin (vs. in front).

Barbatula linjiangensis is further distinguished by having a blunt snout (vs. pointed in B. liaoyangensis ), the upper jaw only partly covered by the upper lip (vs. completely covered in B. toni , B. gibba , B. pechiliensis and B. liaoyangensis ), a slightly convex dorsal profile (vs. convex in B. toni , B. gibba and B. pechiliensis ) and 7½ branched rays of dorsal fin (vs. 6½ in B. potaninorum ).

See Table 3 for the character states shown by the different species of Barbatula found in north-eastern China.

Description. See Figure 26–27 for general appearance and Table 2 for morphometric data. Body elongate, roundish; caudal peduncle compressed. Dorsal profile slightly convex, parallel with ventral profile; caudalpeduncle depth 61–73% of body depth at dorsal-fin origin. Ventral profile between anal-fin base and caudal-fin origin concave. Head wider than deep, head depth 74–97% in its width at posterior margin of operculum. Mouth inferior and arched ( Fig. 28a ). Snout rounded, long and blunt; head width at posterior margin of operculum 1.4–1.5 times in its width at anterior nostril. Snout length equal to postorbital head length. Eye large and close to dorsal profile. Anterior and posterior nostril closely set ( Fig. 28b ). Caudal fin truncate. Caudal-peduncle length 82–104% in HL, caudal-peduncle width 40–50% its depth. Distance between anus and anal-fin origin shorter than eye diameter. Dorsal-fin origin situated at middle or behind middle between tip of snout and caudal-fin base. Pelvic-fin origin situated below vertical through dorsal-fin origin. Anal-fin origin anterior to midpoint between pelvic-fin origin and caudal-fin base.

Lateral line complete, reaching to caudal-fin base. Scales sparsely set on flank anterior to dorsal-fin origin, absent on back and belly anterior to dorsal-fin origin, sparsely set on back and flank behind dorsal-fin origin, densely set on caudal peduncle. Scales sparsely set between pelvic-fin origin and anus. Scales on caudal peduncle with small focal zone and 29–33 radial grooves ( Fig. 28c ). Anterior nostril with short tube, posterior tube shorter or without. Width of anterior nostril much smaller than width of posterior nostril ( Fig. 28b ). Upper jaw not partly covered by upper lip. Upper lip with shallow median incision, its depth 10–30% of width of upper lip. Lower lip widely separate in middle. Mental lobe flattened, without expansion. Interspace between mental lobes narrowly exposing a small part of lower jaw. Lower lip without lateral expansion ( Fig. 28a ). Maxillary barbel usually reaching to posterior eye-margin, inner rostral barbel usually reaching to posterior margin of posterior nostril, outer rostral barbel usually reaching anterior margin of anterior nostril. In few individuals, barbels slightly shorter.

Dorsal fin with 4 unbranched and 7½ branched rays. Anal fin with 2 unbranched and 5½ branched rays. Caudal fin with 7–8+8 branched rays. Pectoral fin with 1 unbranched and 10–11 branched rays. Pelvic-fin with 1 unbranched and 6–7 branched rays. Infraorbital canal confluent with occipital canal, not confluent with supraorbital canal. Infraorbital canal with 12–14, supraorbital with 8–9, occipital with 3, mandibular and preopercular with 13–14 pores. Intestine Z-shaped, anterior margin of zigzag loop not touching U-shaped stomach.

Colouration in alcohol. Background colour pale yellow with dark-brown pattern. Head with two dark-brown lines on both sides of snout in life. Back with 13–15 large, dark-brown bars. Interspaces between the bars narrower than width of them. Flank with large cloudy speckles. Dorsal fin hyaline with 3–5 dark-brown bands formed by spots. Pectoral and pelvic fins hyaline without pigmentation or with few dark-brown spots. lack stripe extends from eye to insertion of maxillary barbel.

Sexual dimorphism. Males have a longer pectoral-fin than females (pectoral-fin length 17–19% SL vs. 13– 15% in female) and the 2nd–7rd branched pectoral-fin rays are thickened in males (vs. not in female).

Distribution. Known from the Yalu River drainage. The Yalu River forms the border between China and North Korea and we expect B. linjiangensis also to occur in North Korea. See Figure 2 for details.

Etymology. The name of the species is derived from its type locality in the Chinese Linjiang City. An adjective.

Figures

FIGURE 2. Map showing the collection sites. Details for each number are listed in material examined.

FIGURE 26. Barbatula linjiangensis, from the top: HU1608016, holotype, 81.0 mm SL; HU1609239, 83.8 mm SL; HU1608904, 79.2 mm SL; China: Liaoning prov.: Yalu River drainage.

FIGURE 27. Barbatula linjiangensis, from the top: HU1608016, holotype, 81.0 mm SL; HU1609239, 83.8 mm SL; HU1608904, 79.2 mm SL; China: Liaoning prov.: Yalu River drainage.

FIGURE 28. Barbatula linjiangensis, HU1608016, holotype, 81.0 mm SL; China: Liaoning prov.: Yalu River drainage. Scale bars: a–b = 1 mm, c = 0.1 mm.