Barbatula emuensis, 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 : 19-22

Barbatula emuensis , new species

( Fig. 19–22 )

Holotype. HU 1608142, 99.9 mm SL; China: Jilin prov.: Zhu’Erduo River near Emu, upper Mudan River flowing into Songhua River of the middle Heilongjiang River drainage, 43°75′N 128°15′E (18); Hao Chen , Aug. 2016.

Paratypes. HU 1608009–10, 1608154, 3, 60.3–72.3 mm SL; same data as holotype .

Additional material examined. HU1609270–71, HU1609265–68, 1608312, 1608317–18, 9, 88.6–96.7 mm SL; China: Jilin prov.: Erdaobai River 10 km east of Songjiangzhen, lower Songhua River of the middle Heilongjiang River drainage, 42°58′N 128°19′E (17); Hao Chen, Aug. 2016.— HU 1608859–64, 6, 70.0– 122.6 mm SL; FSJF 4046 , 3 , 94.8 – 106.1 mm SL, China: Liaoning prov.: Hun River north of North-Shihadacun in Benxi Huanren Manchu Autonomous, upper Yalu River drainage, 41°24′N 125°34′E (15); Hao Chen , May 2017 .— HU 1609190–92, 1609196, 1609201, 5, 85.3–114.2 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 .

Material used in the molecular genetic analysis. HU 1608010; China: Jilin prov.: Zhu’Erduo River, upper Mudan River flowing into Songhua River of the middle Heilongjiang River drainage, 43°75′N 128°15′E, (18). (GenBank accession number: KY451932 ).—HU 1608860; China: Liaoning prov.: Hun River, upper Yalu River drainage, 41°24′N 125°34′E (15). (GenBank accession number: MF770518 ).—HU 1609192; China: Liaoning prov.: Pushi River, Yalu River drainage, 40°68′N 124°73′E (14). (GenBank accession number: MF770519 ).—HU 1609192; China: Jilin prov.: Erdaobai River, lower Songhua River of the middle Heilongjiang River drainage, 42°58′N 128°19′E (17). (GenBank accession number: MF770520 ).

Diagnosis. Barbatula emuensis 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 species discussed above except B. nuda , by no lateral expansion of the lower lip (v s. having) and closely set nostrils (vs. widely spaced).

Barbatul a emuensis is distinguished from B. nuda by the snout being shorter than (vs. equal to) the postorbital head length, having sparsely set scales on the flank anterior to the vertical through the dorsal-fin origin (vs. no scales anterior to the vertical through the dorsal-fin origin) and the pelvic-fin origin in front of the vertical through the dorsal-fin origin (vs. below).

Barbatula emuensis is further distinguished by having a deep median incision in the upper lip, its depth is 50– 70% of the width of the upper-lip (vs. shallow in B. toni , B. potaninorum , B. kirinensis and B. pechiliensis ), a lateral expansion of the mental lobe (vs. with expansions in B. pechiliensis ), the upper jaw partly covered by the upper lip (vs. completely covered in B. toni and B. pechiliebsi ), a slightly convex dorsal profile (vs. convex in B. toni , B. gibba and B. pechiliensis ) and 7½ branched dorsal-fin rays (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 19–20 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 60–74% of body depth at dorsal-fin origin. Ventral profile between anal-fin base and caudal-fin origin concave. Head wider than deep, head depth 73–96% in its width at posterior margin of operculum. Mouth inferior and arched ( Fig. 21a ). Snout rounded, short and blunt; head width at posterior margin of operculum 1.3–1.4 times in its width at anterior nostril. Snout length shorter than postorbital head length. Eye moderately large and close to dorsal profile. Anterior and posterior nostril closely set ( Fig. 21b ). Caudal fin truncate. Caudal-peduncle length 70–99% in HL, caudal-peduncle width 40–62% its depth. Distance between anus and anal-fin origin shorter than or equal to eye diameter. Dorsal-fin origin situated behind middle between tip of snout and caudal-fin base. Pelvic-fin origin in front of dorsal-fin origin. Anal-fin origin at middle 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, flank and belly behind dorsal fin origin; densely set on caudal peduncle. Scales on caudal peduncle fan-shaped, with a moderately small focal zone close to margin and 25–27 radial grooves ( Fig. 21c ). Anterior nostril with long tube, posterior nostril short or without. Width of anterior nostril smaller than or equal to width of posterior nostril. Upper jaw partly covered by upper lip ( Fig. 21b ). Upper lip with deep median incision, its depth 50–70% of width of upper lip. Lower lip widely separate in middle. Mental lobe without expansion. Interspace between mental lobes widely exposing small part of lower jaw. Lower lip without lateral expansion ( Fig. 21a ). Maxillary barbel usually reaching to middle or posterior half of eye, inner rostral barbel usually reaching to posterior or anterior nostril, outer rostral barbel usually reaching to anterior half or middle of snout. 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 7–8, occipital with 3, mandibular and preopercular with 9–11 pores. Intestine Z-shaped, anterior margin of zigzag loop not touching U-shaped stomach.

Colouration in preservative. Background colour pale yellow with dark-brown pattern. Back with 11–13 large, dark-brown bars. Interspaces between the bars narrower than width of them. Flank with large cloud-like mottling. Caudal fin hyaline with 3–4 dark-brown bands formed by spots. 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.

Sexual dimorphism. Males have a longer pectoral-fin than females (pectoral-fin length 16–18% SL vs. 12– 15% in female) and the 2nd–7rd branched pectoral-fin rays are thickened in males (vs. not in female). See Figure 22 for details.

Distribution. Known from the Zhu’Erduo and Erdaobai Rivers. These rivers are tributaries of the Heilongjiang River. It is also found in the Hun and Pushi Rivers, which are tributaries of the Yalu River. The Yalu River forms the border between China and North Korea and we expect B. emuensis 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 Emu City. An adjective.

Figures

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

FIGURE 19. Barbatula emuensis, from the top: HU1608142, holotype, 99.9 mm SL; China: Jilin prov.: Heilongjiang River drainage; HU1608860, 122.6 mm SL; HU1609191, 114.2 mm SL; China: Liaoning prov.: Yalu River drainage.

FIGURE 20. Barbatula emuensis, from the top: HU 1608142, holotype, 99.9 mm SL; China: Jilin prov.: Heilongjiang River drainage; HU1608860, 122.6 mm SL; HU1609191, 114.2 mm SL; China: Liaoning prov.: Yalu River drainage.

FIGURE 21. Barbatula emuensis, HU1608142, holotype, 99.9 mm SL; China: Jilin prov.: Heilongjiang River drainage. Scale bars: a–b = 1 mm, c = 0.1 mm.

FIGURE 22. Barbatula emuensis, proximal part of pectoral fin; a: HU1608861, female, 108.9 mm SL; b: HU1708212, male, 120.2 mm SL; China: Liaoning prov.: Yalu River drainage.