Barbatula restricta, Prokofiev, Artem M., 2015

Prokofiev, Artem M., 2015, A new species of Barbatula from the Russian Altai (Teleostei: Nemacheilidae), Zootaxa 4052 (4), pp. 457-464 : 458-463

Barbatula restricta , new species

( Figs. 1–5 )

Holotype. ZIN 52587, male, 115 mm SL; Russia: Altai Republic: Saldan-Kol (= Dlinnoye) Lake, 50˚13’00’’N 89˚15’30’’E, 2272 m a.s.l., Builyukem River catchment, Chuya River system, upper Ob drainage; 19–20. Aug. 2000, A. S. Golubtsov.

Paratypes. ZIN 52587a, 13 (2 cleared & stained), 80–112 mm SL, same data as holotype.

Diagnosis. Barbatula restricta is distinguished from all other species of Barbatula in Asia by its body depth continuously increasing between the nape and the dorsal-fin origin (vs. uniform in depth at least between the vertical through the mid-length of the adpressed pectoral fin and the dorsal-fin origin), and from all species except B. markakulensis by the tips of the paired fins being always formed by the 1st and 2nd branched rays (vs. 2nd or 2nd and 3rd). Barbatula restricta is also distinguished from B. markakulensis by the absence of well-defined saddles on the back (vs. presence) and in somewhat higher vertebral count (42–45, usually 44 vs. 41–43, usually 42).

Description. For general appearance see Fig. 1 ; morphometric data are provided in Table 1 . Body elongate, cylindrical in front of dorsal-fin origin and laterally compressed behind dorsal-fin base; dorsal contour straight, increasing continuously in depth between nape and dorsal-fin origin. Caudal peduncle compressed, shorter than head, 2.0–2.3 times longer than deep. Head depressed; snout obtuse, not compressed laterally, equal to or greater than postorbital head length; eyes situated dorsolaterally; space between anterior and posterior nostril 1.0–1.5 times in length of posterior nostril. Mouth ( Fig. 2 ) inferior, strongly arched; processus dentiformis small, notch on lower jaw absent; lips moderately furrowed; upper lip with a short median incision; lower lip with small, oval, posteriorly pointing mental lobes, without lateral expansions. Inner and outer rostral barbels reaching a level of anterior and posterior nostrils, respectively; maxillary barbel reaching to vertical through posterior eye margin.

Lateral line complete, with 70–80 pores, reaching to caudal-fin base. Supraorbital canal complete, not confluent with infraorbital canal; supratemporal commissure confluent with infraorbital canal. Pores in cephalic sensory canal system: 7–8 in supraorbital canal, 10–12 in infraorbital canal, 7–9 in preoperculomandibular canal, 3 in supratemporal commissure.

Dorsal fin with 3–4 (usually 3) unbranched and 7 branched rays, with a straight distal margin, its origin closer to caudal-fin base than to tip of snout. Anal fin with 2–3 (usually 2) unbranched and 5 branched rays, with a straight to slightly convex distal margin. Pectoral fin with 1 unbranched and 10–12 (usually 12) branched rays; pelvic fin with 1 unbranched and 6–8 (usually 7) branched rays. Tips of paired fins formed by 1st and 2nd branched rays. Pectoral fin 1.2 times longer than pelvic fin, pectoral fin not reaching halfway to pelvic-fin origin when pressed to flank. Pelvic-fin origin below dorsal-fin origin or slightly behind it, not reaching to anus. Caudal fin emarginate, upper lobe as long as lower one. Branched caudal-fin rays 8 + 8.

Flank and back behind dorsal-fin origin covered by scales. Scales with a small eccentric to moderately large subcentral focal zone ( Fig. 3 ). Flank and back in front of dorsal-fin base without scales or with few isolated scales between the pectoral-fin tip and dorsal-fin origin. Intestine forming a small coil, not touching ventral margin of stomach ( Fig. 4 ). Anus situated about one eye diameter in front of anal-fin origin. Free portion of gas bladder absent.

Osteology. Sphenotic contacting epiotic, lateral fontanelle absent. Supraethmoid-ethmoid fused with prevomer. Urohyal elongate (length:height ratio 2.3–2.6), with deeply indented posterior margin. Basibranchial–4 absent; two pharyngobranchials. Distal margin of neural complex flat, slightly concave in posterior third. Posterior processes of gas-bladder capsule very weak. Vertebrae 42–45 (mean 44, n = 14). Five hypurals. See details in Prokofiev (2007: Fig. 14).

Coloration in preservative. Background colour pale-yellowish to whitish with brownish-gray to dark-brown pattern. Dorsal and lateral parts of head and body mottled with small irregular dark-brown blotches sometimes extending onto belly, sometimes larger and more pronounced on back; no dorsal saddles; ventral surface of head and body pale-yellowish or whitish without colour pattern, a mottled belly in some individuals. All fin rays marked with pronounced brownish-gray blotches forming irregular transverse streaks. Peritoneum pale-whitish, with scattered black melanophores more densely set along vertebral column.

Etymology. The specific epithet is made from the Latin word “restrictus” (restricted) referring to a narrow distribution of this species. An adjective.

Distribution and conservation. Barbatula restricta is only known from the Lake Saldan-Kol (= Dlinnoye) basin, which drains to the Builyukem River. The Builyukem River flows to the upper Chuya, a headwater river of the Ob in south-western Siberia ( Fig. 5 ). It was found to be quite abundant in the lake and its tributaries, mostly in the lowermost part of small creeks flowing into lake (A. S. Golubtsov, personal communication, 2001). The Builyukem River basin has not been searched for this species. It was not found in the main channel of the Chuya River. This is a species with a very small known range (about 30 km 2) and it might be sensitive to pollution and the destruction of habitats. Currently, the species seems not to be threatened.

Remarks. Twelve species of Barbatula are currently recognized as valid in Asia. Three additional nominal species ( B. cobdonensis , B. compressirostris and B. shansi ) are very poorly studied though they might represent valid species ( Table 2 ).

Barbatula cobdonensis has been described by Gundriser (1973) from the upper Chovd River drainage. The type series of B. cobdonensis might have been lost ( Prokofiev 2007), and no fresh material from the type locality was available for this study. Barbatula restricta is distinguished from the fishes described as B. cobdonensis by Gundriser (1973; 1979) by having 7 branched dorsal-fin rays (vs. 8–9), 5 branched anal-fin rays (vs. 6) and the posterior flank covered by scales (vs. scaleless). A Barbatula species from the upper Chovd River drainage has been characterized as “Chulug-Khol form” by Prokofiev (2007). The “Chulug-Khol form” is quite different from the fishes described as B. cobdonensis by Gundriser (1973; 1979) by having 7 branched dorsal-fin rays (vs. 8–9), 5 branched anal-fin rays (vs. 6) and plain grayish- to olive-yellowish flanks (vs. irregularly mottled). This finding indicate, that two Barbatula species might be found in the upper Chovd River drainage.

Barbatula compressirostris might to be a synonym of B. toni ( Prokofiev (2014) (“blunt-nosed” form in Prokofiev (2007)) or a valid name for the species described as Nemacheilus barbatulus morpha tigris by Gundriser (1975). Barbatula restricta is distinguished from the syntypes of B. compressirostris by having the maximal body depth at dorsal-fin origin (vs. at the vertical of the mid-length of the adpressed pectoral fin), the tips of the paired fins formed by the 1st and 2nd branched rays (vs. 2nd and 3rd), a body covered by scales (vs. scaleless) and the absence of the dark-brown saddles on the back (vs. presence).

Barbatula stoliczkai shansi was described by Nichols (1925) from the vicinity of Baotou, Nei Monggol province of China and was listed in the synonymy of B. nuda by Kottelat (2012: 78). Barbatula stoliczkai shansi was not considered by Cao et al. (2012) in their study of Chinese Barbatula . It may be a member of Barbatula or even another genus as Triplophysa . Here it is not possible to provide a differential diagnosis between B. restricta and B. stoliczkai shansi as the description of B. stoliczkai shansi is uninformative and no materials of this species was available for this study. It is very hard to imagine, that both might be conspecific, as B. restricta is only known from the upper Ob drainage while B. stoliczkai shansi was found in the area of the middle Huanghe River drainage (42 miles east of Baotou) and both areas are about 2000 km apart from each other.

From all known Barbatula species in Asia, B. restricta can be easily distinguished by its body depth increasing continuously between the nape and the dorsal-fin origin (vs. uniform in depth at least between the vertical through mid-length of the adpressed pectoral fin and the dorsal-fin origin). It can be further distinguished from all species except B. markakulensis by the more pointed pectoral and pelvic fins. The tips of these fins are formed by the 1st and 2nd branched rays (vs. 2nd or 2nd and 3rd). Besides its body shape, B. restricta differs from B. markakulensis by a higher number of vertebrae (42–45, mean 44 vs. 41–43, mean 42) and the absence of well-defined saddles on the back (vs. present).

Prokofiev (2007; 2014) treated B. markakulensis as a synonym of B. toni . The loaches from the Lake Markakul basin are distinguished from all other populations referred to B. toni by the difference in the tip of the paired fins, which is formed by the 1st or 1st and 2nd branched rays (vs. 2nd or 2nd and 3rd). Therefore, B. markakulensis is treated here as a valid species. Barbatula markakulensis is restricted to the Lake Markakul basin which is situated in the Irtysh River drainage in Kazakhstan; a record from Bulgan-Gol ( Mongolia) ( Kottelat 2012) is erroneous ( Prokofiev 2014).

Two other Barbatula species are currently recognized in the upper Ob drainage: B. toni and B. tomiana . Barbatula toni is widespread while B. tomiana is restricted to the upper parts of the Ob basin in Altai, where this species co-occurs with B. toni in many localities. Barbatula restricta can be easily distinguished from these species in its body shape and acute paired fins as described above. Besides the problematic “ Nemacheilus cobdonensis ” and the “Chulug-Khol form” discussed above, the only other adjacent species to B. restricta is B. golubtsovi from the Chovd basin in Russia and Mongolia. See below to distinguish B. restricta from B. golubtsovi .

Barbatula restricta can be further distinguished from B. altayensis , B. minxianensis , B. nuda and B. sawadai by having widely spaced nostrils (vs. closely set); from B. dgebuadzei , B. golubtsovi , B. nuda and B. sawadai by having a short median incision in the upper lip (vs. deep); from B. dgebuadzei , B. golubtsovi , B. nuda and B. tomiana by having the flanks covered by scales (vs. scaleless); from B. altayensis by the presence of mental lobes at the lower lip (vs. absence); from B. dgebuadzei , B. golubtsovi and B. sawadai by the absence of conical protrusions on the mental lobes of the lower lip (vs. presence); from B. minxianensis , B. nuda and B. toni by the absence of saddles on the back (vs. always present and well-marked; also occasionally present in B. dgebuadzei and B. tomiana ); from B. dgebuadzei , B. golubtsovi , B. sawadai and B. tomiana by the pale-whitish peritoneum (vs. brownish; peritoneal coloration is not known for B. altayensis and B. minxianensis ); from B. dgebuadzei and B. golubtsovi by the absence of the lateral expansions of the lower lip (vs. lateral expansions moderate to long); from B. dgebuadzei and B. potaninorum by the pelvic-fin origin situated at or slightly behind the dorsal-fin origin (vs. in front); from B. dgebuadzei by the continuous supratemporal commissure with 3 pores (vs. interrupted, 2+2 pores); from B. golubtsovi by the lower vertebral count (42–45 vs. 45–47) and by the smooth skin (vs. warty), and from B. tomiana by the obtuse snout (vs. pointed).

Osteological characters are known from B. dgebuadzei , B. golubtsovi , B. sawadai , B. tomiana and B. toni . Barbatula restricta can be distinguished from B. toni by the fused supraethmoid-ethmoid and prevomer (vs. separate); from B. dgebuadzei by the absence of basibranchial–4 (vs. presence) and flat, posteriorly concave distal margin of the neural complex (vs. triangular); from B. sawadai by the absence of the contact between the parietal and pterotic (vs. presence); and from B. tomiana by the deeply indented posterior margin of the urohyal (vs. irregularly incised).

Barbatula oreas from Japan (Hokkaido) and South Korea is not included in the aforementioned analysis due to the lack of materials and the very limited literature data describing this species ( Jordan & Fowler, 1903; Sawada, 1982). Following the information provided by Sawada (1982), B. restricta is distinguished from B. oreas by having 42–45, usually 44 total vertebrae (vs. 37–39).

Figures

FIGURE 5. Occurrence of B. restricta (star).

FIGURES 1 – 4. Barbatula restricta, holotype, ZIN 52587, 115 mm SL: (1) lateral view; (2) mouth structure; (3) scales from flanks under dorsal-fin base (focal zone arrowed); (4) gastro-intestinal tract. Abbreviations: mi—medial indentation of upper lip, ml—mental lobe of lower lip, prd—processus dentiformis. Scale bars: 2 — 2.5 mm, 3 — 0.2 mm, 4 — 5.0 mm.

Tables

TABLE 1. Morphometric data of Barbatula restricta (ZIN 52587 and 52587 a; n = 14).

mm SL	Holotype 115	Paratypes Range 80–112	Mean –	SD –
In percent of SL Head length Greatest body depth	20.4 13.4	20.0–23.3 11.7–15.3	21.5 13.8	1.2 1.1
Least depth of caudal peduncle Greatest body width	7.9 13.0	7.6–10.3 11.7–14.4	8.5 13.2	0.8 1.9
Caudal-peduncle length Predorsal distance Preanal distance Prepelvic distance	18.5 53.7 74.1 53.7	17.0–19.4 50.5–55.9 73.2–76.3 50.5–55.9	18.1 52.9 74.7 52.9	0.8 1.9 1.1 1.8

TABLE 2. Nominal and valid species of the genus Barbatula in Asia.

Nominal taxon	Current status	Sources
Barbatula altayensis Zhu 1992	Barbatula altayensis	Zhu (1992); Prokofiev (2007); Cao et al. (2012)
Nemachilus cobdonensis Gundriser 1973	Unclear	Prokofiev (2007; 2014)
Nemachilus compressirostris Warpachowsky 1897	Uncertain, either Barbatula toni or a valid name for Nemacheilus barbatulus morpha tigris of Gundriser (1975)	Prokofiev (2014)
Orthrias dgebuadzei Prokofiev 2003	Barbatula dgebuadzei	Prokofiev (2007); Kottelat (2012)
Barbatula toni fowleri Nichols 1925	Barbatula toni	Cao et al. (2012)
Barbatula gibba Cao, Causse et E Zhang 2012	Barbatula toni	Prokofiev (2014)
Orthrias golubtsovi Prokofiev 2003	Barbatula golubtsovi	Prokofiev (2007); Kottelat (2012)
Barbatula toni kirinensis Tchang 1932	Barbatula toni	Cao et al. (2012)
Barbatula restricta Prokofiev , new species	Barbatula restricta	Present contribution
Nemacheilus barbatulus markakulensis Menshikov 1939	Barbatula markakulensis	Present contribution
Nemachilus minxianensis Wang & Zhu 1979	Barbatula minxianensis	Prokofiev (2014)
Nemacheilus nudus Bleeker 1865	Barbatula nuda	Cao et al. (2012)
Orthrias oreas Jordan & Fowler 1903	Barbatula oreas	Prokofiev (2007); Kottelat (2012)
Nemachilus pechiliensis Fowler 1899	Might be a senior synonym of Barbatula potaninorum	Cao et al. (2012)
Orthrias potaninorum Prokofiev 2007	Barbatula potaninorum	Prokofiev (2007); Kottelat (2012)
Orthrias sawadai Prokofiev 2007	Barbatula sawadai	Prokofiev (2007); Kottelat (2012)
Barbatula stoliczkai shansi Nichols 1925	Unclear	Nichols (1925); Kottelat (2012)
Nemacheilus sibiricus Gratzianow 1907	Barbatula toni	Prokofiev (2014)
Nemacheilus barbatulus morpha tigris Gundriser 1975	Invalid name (infrasubspecific)	Prokofiev (2007)
Nemacheilus barbatulus tomianus Ruzsky 1920	Barbatula tomiana	Dgebuadze et al. (2009); Prokofiev (2014)
Cobitis Toni Dybowski 1869	Barbatula toni	Prokofiev (2007; 2014); Cao et al. (2012)