Barbatula liaoyangensis, 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 : 22-25

Barbatula liaoyangensis , new species

( Fig. 23–25 )

Holotype. HU 1608150, 75.9 mm SL; China: Liaoning prov.: Taizi River east of Xiaobeihezhen, Liao River drainage, 41°36′N 122°85′E (12); Hao Chen , Oct. 2016.

Paratypes. HU 1608320, 1608152, 1608851–59, 11, 62.1–89.8 mm SL, FSJF 4047 , 2 , 69.2 – 71.8 mm SL ; same data as holotype .

Additional material examined. IHB 88 v0139, 88v 0143, 88v 0152–53, 88v 0155–57. 7, 65.9–105.9 mm SL; China: Liaoning prov.: Taizi River at Liaoyang, Liao River drainage (12) .

Material used in the molecular genetic analysis. HU 1608278–79, 1608320; China: Liaoning prov.: Taizi River, Liao River drainage, 41°36′N 122°85′E (12). (GenBank accession numbers: KY451929 –31).

Diagnosis. Barbatula liaoyangensis is distinguished from all other species of Barbatula in north-eastern China by having a pointed snout, head width at posterior margin of operculum 1.5–1.8 times in its width at anterior nostril (vs. blunt, 13–1.4).

Barbatula liaoyangensis is further distinguished from the other species of Barbatula in north-eastern China by a combination of characters, none of them unique. It is distinguished by having the nostrils widely spaced (vs. closely set in B. nuda and B. emuensis ), the snout being shorter than (vs. equal to in B. nuda and B. toni ) the postorbital head length, a shallow median incision in the upper lip, its depth 10–30% of the width of the upper-lip (vs. deep, 40–70% in B. nuda , B. gibba and B. emuensis ), a blade-shaped lateral expansion of the mental lobe (vs. without expansion in B. nuda , B. gibba , B. toni , B. kirinensis and B. emuensis ), the upper jaw completely covered by the upper lip (vs. partly covered in B. nuda and B. kirinensis ), a slightly convex dorsal profile (vs. convex in B. toni and B. pechiliensis ), 7½ branched dorsal-fin rays (vs. 6½ in B. potaninorum ) and sparsely set scales on the flank anterior to the vertical through the dorsal-fin origin (vs. without scales anterior to dorsal-fin origin in B. nuda , B. gibba and B. pechiliensis ).

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

Description. See Figure 23–24 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 59–68% of body depth at dorsal-fin origin. Ventral profile between anal-fin base and caudal-fin origin concave. Head wider than deep, head depth 75–94% in its width at posterior margin of operculum. Mouth inferior and arched ( Fig. 25a ). Snout rounded, short and pointed; head width at posterior margin of operculum 1.5– 1.8 times in its width at anterior nostril. Snout shorter than postorbital head length. Eye small, set close to dorsal profile. Anterior and posterior nostril widely spaced, gap between nostrils equal or shorter than width of base of posterior nostril ( Fig. 25b ). Caudal fin truncate. Caudal-peduncle length 75–97% in HL, caudal-peduncle width 45–65% 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 situated below vertical through dorsal-fin origin or in front. 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 on caudal peduncle with small focal zone and 24–26 radial grooves ( Fig. 25c ). Anterior nostril formed by short tube, posterior tube shorter or without tube. Width of anterior nostril equal to width of posterior nostril ( Fig. 25b ). Upper jaw unexposed, completely covered by upper lip. Upper lip with very shallow median incision, its depth 10–30% of width of upper lip. Lower lip widely separated in middle. Mental lobe with blade-shaped lateral expansion. Interspace between mental lobes narrow, exposing small part of lower jaw. Lower lip with short lateral expansion, its length 30–40% of width of upper-lip ( Fig. 25a ). Maxillary barbel usually reaching to anterior half or middle of eye, inner rostral barbel usually reaching to posterior margin of anterior nostril, outer rostral barbel usually reaching to 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 8–9, occipital with 3, mandibular and preopecular 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. Back with 11–13 large, dark-brown bars. Interspaces between the bars equal to width of them. Flank with large cloud-like mottling. Caudal fin hyaline with 5–6 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 15–16% SL vs. 12– 15% in female) and the 2nd–7rd branched pectoral-fin rays are thickened in males (vs. not in female).

Distribution. Known from the Taizi River, a tributary of the Liao River. See Figure 2 for details.

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

Figures

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

FIGURE 23. Barbatula liaoyangensis, from the top: HU 1608150, holotype, 75.9 mm SL; HU1608320, 75.9 mm SL; IHB88v0157, 74.2 mm SL; China: Liaoning prov.: Liao River drainage.

FIGURE 24. Barbatula liaoyangensis, from the top: HU1608279, paratype, 82.3 mm SL; HU1608320, 75.9 mm SL; IHB88v0157, 74.2 mm SL; China: Liaoning prov.: Liao River drainage.

FIGURE 25. Barbatula liaoyangensis, HU1608150, holotype, 75.9 mm SL; China: Liaoning prov.: Liao River drainage. Scale bars: a–b = 1 mm, c = 0.1 mm.