Research Article
Print
Research Article
Triplophysa wulongensis, a new species of cave-dwelling loach (Teleostei, Nemacheilidae) from Chongqing, Southwest China
expand article infoShijing Chen, Bakhtiyor Sheraliev§, Lu Shu, Zuogang Peng
‡ Southwest University, Chongqing, China
§ Fergana State University, Fergana, Uzbekistan
Open Access

Abstract

We describe a new species of cave-dwelling loach, Triplophysa wulongensis sp. nov., based on specimens collected in a subterranean pool in a cave in Wulong County, Chongqing, Southwest China. The pool is connected to the Wujiang River drainage. Triplophysa wulongensis differs from its congeners by the following combination of characters: eyes present, caudal fin with 18 branched rays; posterior chamber of the air bladder degenerate; stomach U-shaped; intestine without bends or loops immediately posterior to stomach; body smooth and scaleless, and lateral line complete. The mitochondrial cytochrome b sequence differs from those of other published sequences of species of Triplophysa by 14.9–24.9% in K2P distance. Phylogenetic analysis based on cytochrome b gene sequences recovered T. wulongensis as sister taxon to all other cave-dwelling species of Triplophysa.

Keywords

Cavefish, cytb sequence, freshwater fish, ichthyology, phylogeny

Introduction

The genus Triplophysa Rendahl, 1933, currently comprises approximately 160 valid species, most of which are known from Qinghai-Tibet Plateau and to a lesser extent from Central Asia (Zhu 1989; Prokofiev 2010; Kottelat 2012; Fricke et al. 2020). Triplophysa is distinguished from other genera of Nemacheilidae by a marked sexual dimorphism, in which males have tubercle-bearing, elevated skin on the side of the head, and a thickened tuberculated pad on the dorsal surface of the thickened and widened rays of the pectoral fin. Species of Barbatula Linck, 1790 share the same sexual dimorphism, but Triplophysa can be distinguished from Barbatula by the closely situated nostrils (Bănărescu and Nalbant 1968; Prokofiev 2010; Yang et al. 2012; Liu et al. 2017).

To date, 33 cave-dwelling species of Triplophysa have been described from the karst areas of southern China where karst caves and subterranean streams are dominant geological features (Lan et al. 2013; Liu et al. 2017; Wu et al. 2018a). According to Lan et al. (2013), these species can be placed into three groups based on the state of the eyes, namely, eyes normal, reduced, or absent (Table 1).

Table 1.

Characters variable across cave-dwelling species of Triplophysa from China.

No Species Eyes Scales Lateral line Posterior chamber of air bladder Dorsal Anal Pectoral Pelvic Caudal Tip of pelvic fin reaching anus Anterior nostril barbel-like
fin rays fin rays fin rays fin rays fin rays
1. T. aluensis Reduced Absent Complete Degenerated iii, 7 iii, 5 i, 9 i, 6 13 No Yes
2. T. anshuiensis Absent Absent Complete Developed iv, 7–8 ii, 6 i, 10 i, 6 14 Yes Yes
3. T. baotianensis Normal Absent Complete Degenerate iii, 6–7 ii, 4–5 i, 9 i, 5 11–13 No Yes
4. T. erythraea Absent Absent Complete Developed ii, 8 i, 6 ii, 10 ii, 5 17 Yes No
5. T. fengshanensis Absent Absent Complete ii, 8 ii, 6 i, 8–10 i, 6–7 16 No Yes
6. T. flavicorpus Normal Present Complete Degenerated iii, 10 iii, 6–7 i, 11 i, 6–7 16 Yes No
7. T. gejiuensis Absent Absent Complete Developed iii, 7–8 iii, 4–6 i, 10 i, 5 14–15 Yes Yes
8. T. guizhouensis Normal Present Complete Developed iii, 8 iii, 6 i, 8–9 i, 6 14 No Yes
9. T. huanjiangensis Absent Absent Absent Developed iii, 8–9 iii, 6–7 i, 10–14 i, 6–7 13–14 No Yes
10. T. huapingensis Normal Present Complete Degenerated iii, 8–9 iii, 5 i, 9–10 i, 5–6 16 No No
11. T. langpingensis Reduced Absent Incomplete iii, 7–8 iii, 5–6 i, 10–11 i, 6 14 Yes Yes
12. T. lingyunensis Reduced Present Incomplete Degenerated iii, 7–8 iii, 5 i, 8–9 i, 5–6 16 No Yes
13. T. longipectoralis Normal Present Complete Degenerated iii, 8 iii, 5–6 i, 9–10 i, 6 14–15 Yes Yes
14. T. longliensis Normal Absent Complete Developed iii, 8 iii, 5 i, 10 i, 6 15–16 Yes Yes
15. T. luochengensis Reduced Present Complete Degenerated iii, 8 ii, 6 i, 10 i, 6 16–17 No Yes
16. T. macrocephala Reduced Absent Complete Degenerated iii, 7–9 iii, 5–6 i, 9–11 i, 6 15–17 Yes Yes
17. T. maolanensis Absent Absent Complete iii, 8 ii, 5 i, 11 i, 6 14 Yes No
18. T. nandanensis Normal Present Complete Degenerated iv, 8 iv, 5 i, 9–10 i, 6 14–16 No Yes
19. T. nanpanjiangensis Normal Absent Complete Degenerated iii, 7–8 ii, 5 i, 9–10 i, 6 16 No Yes
20. T. nasobarbatula Normal Present Complete Degenerated iii, 8 iii, 5 i, 9 i, 6 15 Yes Yes
21. T. posterodorsalus Absent Absent Complete iii, 6 ii, 4 i, 13 i, 5 15 No Yes
22. T. qiubeiensis Absent Absent Complete Degenerated iii, 7 iii, 5 i, 7–9 i, 5 14–15 Yes No
23. T. rosa Absent Absent Complete iii, 9 iii, 6 i, 12 i, 7 14 Yes Yes
24. T. sanduensis Normal Present Complete Degenerated ii, 8–9 i, 5 i, 8–9 i, 5 17–18 No Yes
25. T. shilinensis Absent Absent Complete Degenerated iii, 7 iii, 5 i, 8–10 i, 6 14 No Yes
26. T. tianeensis Reduced Absent Complete Degenerated iii, 6–7 iii, 5 i, 8–9 i, 5–6 15–16 No Yes
27. T. tianlinensis Reduced Absent Complete Degenerated iii, 7 iii, 5–6 i, 10 i, 6 15–16 Yes Yes
28. T. tianxingensis Normal Absent Complete Developed iii, 8 ii, 5 i, 9 i, 5 16 No No
29. T. wulongensis sp. nov. Normal Absent Complete Degenerated ii, 8–9 i, 5–6 i, 8–9 i, 5–7 18 No Yes
30. T. xiangshuingensis Normal Absent Complete Degenerated iii, 6 iii, 5 i, 9 i, 6 14 No Yes
31. T. xiangxiensis Absent Absent Complete Developed iii, 8 iii, 6 i, 11 i, 6 16 Yes Yes
32. T. xichouensis Reduced Absent Complete Developed iii, 8 ii, 6 i, 9–10 i, 5–6 16 Yes Yes
33. T. yunnanensis Normal Present Complete Degenerated iii, 7 iii, 5 i, 9–10 i, 7 15–16 No Yes
34. T. zhenfengensis Normal Present Complete Degenerated iii, 7 iii, 5 i, 9 i, 5–7 14–15 No Yes

We collected nine loach specimens from a subterranean pool in a cave located in Wulong County, Chongqing, Southwest China. Morphological and molecular analyses justified the recognition of this sample as representing a new species of Triplophysa, described below.

Materials and methods

After anesthesia, the specimens were fixed in 10% formalin and stored in 70% ethanol. Measurements were made with digital calipers and rounded off to the nearest 0.1 mm. All measurements were made point to point, and whenever possible, measurements and counts were recorded on the left side of the body following the methods described by Kottelat and Freyhof (2007). The standard length was measured from the tip of the snout to the end of the hypural complex; the length of the caudal peduncle was measured from behind the base of the last ray of the anal fin to the end of the hypural complex at mid-height of the base of the caudal fin. The last two branched rays articulating on a single pterygiophore in the dorsal and anal fins were counted as a single ray. Fin rays were counted using a stereo microscope. Vertebrae from five specimens were observed on X-radiographs. The specimens examined were deposited in the Southwest University School of Life Sciences (SWU) in Beibei, Chongqing, P. R. China. Abbreviations are defined as follows: SL, standard length; HL, head length; CLJH, Collection of Lan Jiahu (private collection); GIF, Guangxi Institute of Fisheries, Guangxi, China.

Data on Triplophysa aluensis Li & Zhu, 2000, T. gejiuensis (Chu & Chen, 1979), T. nanpanjiangensis (Zhu & Cao, 1988), T. qiubeiensis Li & Yang, 2008, T. shilinensis Chen & Yang, 1992, T. tianxingensis Yang, Li & Chen, 2016, T. xiangshuingensis Li, 2004 and T. yunnanensis Yang, 1990 are from Yang et al. (2016); T. baotianensis Li, Li, Liu & Li, 2018 and T. longliensis Ren, Yang & Chen, 2012 from Li et al. (2018); T. maolanensis (Li, Ran & Chen, 2006) and T. posterodorsalus (Li, Ran & Chen, 2006) from Li et al. (2006); T. anshuiensis Wu, Wei, Lan & Du, 2018, T. flavicorpus Yang, Chen & Lan, 2004, T. guizhouensis Wu, He, Yang & Du, 2018, T. luochengensis Li, Lan, Chen & Du, 2017 and T. tianlinensis Li, Li, Lan & Du, 2016 from Wu et al. (2018b); T. erythraea Liu & Huang, 2019 and T. xichouensis Liu, Pan, Yang & Chen, 2017 from Huang at al. (2019); and T. xiangxiensis (Yang, Yuan & Liao, 1986) from Yang et al. (1986). Other species used for comparative purposes were examined at CLJH, GIF, and SWU, China (Suppl. material 1: Table S1).

DNA extraction and PCR

Genomic DNA was extracted from ethanol-preserved fin tissue using a DNeasy Blood and Tissue Kit (QIAGEN, Shanghai, China). The primers used for PCR amplification of the mitochondrial cytochrome b (cytb) gene are described by Xiao et al. (2001). PCR amplifications were performed in a total volume of 25 μL consisting of 14.8 μL of dd H2O, 2.0 μL of DNA template (50 ng/μL), 1.0 μL of each primer (10 μM), 2.5 μL of 10× PCR buffer, 1.5 μL of 25 mM MgCl2, 2.0 μL of 2.5 mM dNTPs, and 0.2 μL of rTaq DNA polymerase (TaKaRa; Dalian, China). The PCR conditions used were as follows: an initial denaturation step at 94 °C for 4 min followed by 34 cycles of 30 s at 94 °C, 50 s at 50–56 °C and 80 s at 72 °C; with a final extension of 8 min at 72 °C.

Molecular data analyses

We sequenced partial cytb gene of T. longliensis, T. nandanensis Lan, Yang & Chen, 1995, T. sanduensis Chen & Peng, 2019, T. tianeensis Chen, Cui & Yang, 2004, and T. wulongensis and retrieved the cytb gene sequences for other species of Triplophysa from GenBank (Table 2). Barbatula nuda (Bleeker, 1864) and B. toni (Dybowski, 1869) were selected as outgroup. Alignment of the cytb sequences was performed using the Clustal W algorithm in MEGA7 (Kumar et al. 2016), with manual checks for inconsistencies. MEGA7 was also used to calculate Kimura’s 2-parameter genetic distances (K2P). For phylogenetic reconstructions, the datasets were analyzed based on Bayesian inference (BI) methodology using MrBayes 3.2 (Ronquist et al. 2012) and the maximum likelihood (ML) method of MEGA7 (Kumar et al. 2016). MrBayes used the Generalized Time Reversible model (nst = 6) and gamma-distributed rate variation and the proportion of invariable positions (GTR+G+I) for the cytb datasets. For BI, we ran four simultaneous Monte Carlo Markov chains for 2,000,000 generations, with sampling every 1,000 generations, and the first 25% of samples were discarded as burn-in. Tracer v. 1.7 (Rambaut et al. 2018) was used to assess convergence of the posterior, which was determined when effective sample size (ESS) values reached 200. For ML analyses, we conducted heuristic searches (1,000 runs) using a Kimura’s 2-parameter (K2P) model. The phylogenetic trees were visualized and edited using FigTree v. 1.4.2 (Rambaut 2014).

Table 2.

The species used in this study with their GenBank accession number for the mitochondrial cytb gene sequences.

Species GenBank accession number Species GenBank accession number
Barbatula nuda KF574248 Triplophysa minxianensis KT213596
Barbatula toni AB242162 Triplophysa nandanensis MW582824
Triplophysa anterodorsalis KJ739868 Triplophysa rosa JF268621
Triplophysa bleekeri JQ686729 Triplophysa sanduensis MW582822
Triplophysa brevicauda KT213588 Triplophysa siluroides KT213603
Triplophysa chondrostoma KT213589 Triplophysa tianeensis MW582826
Triplophysa erythraea MG967615 Triplophysa tibetana KT224364
Triplophysa huapingensis MG697589 Triplophysa wulongensis MW582823
Triplophysa lewangensis KU987438 Triplophysa xiangxiensis KT751089
Triplophysa longliensis MW582825 Triplophysa xichangensis KT224366
Triplophysa markehenensis KT213594 Triplophysa zhenfengensis MK610360
Triplophysa microps KT213595

Results

Triplophysa wulongensis sp. nov.

Figures 1, 2; Table 3

Type material

Holotype. SWU2019051309, male, 64.0 mm SL. P.R. China: Chongqing City; Wulong County: subterranean pool in Furong Cave (29°24'1.09"N, 107°54'11.60"E); collected by Ni Liu, May 2019.

Paratypes. SWU2019051301–2019051308, 8 ex., 49.0–67.2 mm SL; collected with the holotype.

Figure 1. 

Triplophysa wulongensis sp. nov., holotype, SWU 2019051309, 64.0 mm SL A lateral view B dorsal view C ventral view.

Diagnosis

Triplophysa wulongensis can be distinguished from its congeners by the following combination of characters: eyes present (vs absent in T. anshuiensis, T. erythraea, T. huanjiangensis Yang, Wu & Lan, 2011, T. rosa Chen & Yang, 2005, T. xiangxiensis and T. posterodorsalus); anterior nostril barbel-like (vs anterior nostril not elongate to barbel-like in T. erythraea, T. flavicorpus, T. huapingensis Zheng, Yang & Chen, 2012 and T. tianxingensis): caudal fin with 18 branched rays (vs 14–16 in T. guizhouensis, T. lingyunensis (Liao, Wang & Luo, 1997), T. nandanensis, T. shilinensis and T. zhenfengensis Wang & Li, 2001), vertebrae 4+38–39 (vs 36–37 in T. nasobarbatula Wang & Li, 2001 and T. sanduensis; 42–43 in T. siluroides); predorsal length 50.4–54.2% of standard length (vs 46.1–48.0% in T. sanduensis); posterior chamber of gas bladder degenerate (vs developed in T. anshuiensis, T. tianxingensis and T. xichouensis); body smooth and scaleless (vs body covered by scales in T. longipectoralis Zheng, Du, Chen & Yang, 2009 and T. yunnanensis); lateral line complete (vs incomplete in T. huanjiangensis); and pelvic-fin tip not reaching to anus (vs reaching to anus in T. gejiuensis, T. macrocephala Yang, Wu & Yang, 2012, T. rosa and T. qiubeiensis).

Description

Morphometric data of the type specimens of T. wulongensis are presented in Table 3. D, 2/8–9; A, 1/5–6; P, 1/8–9; V, 1/5–7; C, 18; vertebrae: 4+38–39 (five specimens).

Table 3.

Morphometric data of type specimens of Triplophysa wulongensis sp. nov. SD = standard deviation.

Morphometric characters Holotype Paratypes (SWU2019051301–08)
SWU2019051309 Min Max Mean SD
SL (mm) 64 49 67.2 55.7
% SL
Lateral head length (HL) 22.9 20.4 23.5 22.6 1
Body depth 13.3 9.3 13.6 12.1 1.3
Predorsal length 54.2 50.4 53.3 51.9 0.9
Postdorsal length 40.7 34 39.4 36.7 1.4
Prepelvic length 49.6 48.3 50.9 49.7 0.9
Preanal length 76 71.5 77.7 73.4 1.8
Preanus length 70 67.4 70.2 69 1
Dorsal-fin height 15.9 15 19.8 16.5 1.5
Dorsal-fin base length 12 10.7 13.4 12.4 0.9
Anal-fin height 14.1 12.4 16.5 14.5 1.3
Anal-fin base length 6.6 6.6 8.2 7.4 0.6
Pelvic-fin length 12.4 12.5 14.5 13.2 0.6
Pectoral-fin length 16.6 15.6 18.4 17.6 1
Caudal-fin length 17.8 15.9 20.8 18.1 1.3
Caudal-peduncle length (CPL) 20.8 14.2 18.4 16.6 1.2
Caudal-peduncle depth (CPD) 9.4 7.6 9.4 8.5 0.7
Pectoral-pelvic distance 26.8 24.6 28.6 26.6 1.1
Pelvic-anal distance 26.4 21.6 26.9 23.7 1.4
Vent-anal fin origin distance 6.2 4 7.2 5.8 1
%HL
Head depth 53.8 45.3 54.2 50.6 2.9
Head width 62.2 55.7 65.8 62.4 3.5
Snout length 39 38.9 45 41.9 1.9
Eye diameter 11.1 12.2 19.1 17 2.1
Interorbital width 38.7 38.5 43.1 41.3 1.5
Postorbital head length 45 37.9 46.8 43.8 2.8
Maxillary barbel length 21.8 27.2 35.9 29.8 3.2
Inner rostral barbel length 16.5 20.1 23.4 21.6 1.2
Outer rostral barbel length 21.4 25.9 41.5 32.4 4.5
CPD/CPL 45.3 44.3 57.4 51.2 4.5

Body elongated, slightly compressed anteriorly and more strongly compressed posteriorly. Deepest point of body in front of dorsal fin origin, body depth 9.3–13.6% of SL. Caudal peduncle depth/caudal peduncle length range from 44.3% to 57.4%. Head depressed, width greater than depth (62.4% vs 50.6% of HL). Snout moderately blunt and snout length almost equal to postorbital length, approximately 38.9–45.0% of HL. Anterior and posterior nostrils adjacently located; anterior nostril in short tube, each with tip elongated to form a short barbel. Tip of nostril appendage not reaching the anterior margin of eyes. Eyes present, diameter 11.1–19.1% of HL. Mouth inferior, arched; mouth corner situated below anterior nostril. Lips thin; lower lip with well-marked, V-shaped, median notch (Fig. 2). Upper jaw covered by upper lip; lower jaw scoop-shaped, not covered medially by lower lip. Three pairs of barbels; inner rostral barbel extending to rictus, 16.5–23.4% of HL; outer rostral barbel not extending to anterior margin of eyes, 21.4–41.5% of HL; maxillary barbel extending to anterior margin of eyes, 21.8–35.9% of HL.

Figure 2. 

Triplophysa wulongensis sp. nov., holotype SWU 2019051309, 64.0 mm SL; head in dorsal and ventral view.

Dorsal fin emarginate, origin posterior to pelvic fin insertion, situated slightly posterior to midpoint between snout tip and caudal fin base; first branched ray longest; dorsal fin height shorter than lateral head length; tip of dorsal fin reaching vertical of anus. Pectoral fin moderately developed, 56.6–72.9% of distance between pectoral fin and pelvic-fin origins. Pelvic-fin origin situated almost at midpoint between pectoral-fin origin and anal-fin origin, tip of pelvic fin not reaching to anus. Anal-fin origin situated almost at midpoint between pelvic-fin origin and caudal-fin base, distal margin of anal fin truncate; posterior tip of anal fin reaching approximately half distance between anal-fin origin and caudal-fin base. Vent-anal fin-origin distance 4.0–7.2% of SL. Caudal fin emarginate.

Body smooth and scaleless. Cephalic lateral line system developed. Lateral line complete, ending at caudal-fin base. Intestine without bends or loops immediately posterior to stomach; stomach U-shaped. Posterior chamber of gas bladder degenerate.

Coloration

In formalin-fixed specimens, body yellowish dorsally, gradually lighter toward ventral side. Fins semitransparent. Body dorsally and laterally covered with irregular, brown blotches; 6–8 distinct dark brown blotches along dorsal midline.

Sexual dimorphism

Sexual dimorphism was not detected. This may reflect that the sampling time was outside the breeding season of this species.

Geographical distribution

Known only from the type series, from a pool in Furong Cave, connected to the Wujiang River near Wulong, (Fig. 3). Triplophysa wulongensis was found syntopic with T. rosa.

Figure 3. 

Collection site of Triplophysa wulongensis sp. nov. (red triangle) in Chongqing, Southwest China.

Etymology

The specific name, wulongensis, refers to the type locality in Wulong County, where the type specimens were collected; it is an adjective with alternative endings -is and -e.

Discussion

In previous studies, the cave dwelling species of Triplophysa were nested in a basal position to congeners in phylogenetic reconstructions (Wang et al. 2016; Chen and Peng 2019; Wu et al. 2020). Our phylogenetic analysis based on cytb (Fig. 4) resolved two monophyletic clades, one of which comprises cave-dwelling species, and the other includes non-cave-dwelling species, concordant with Chen and Peng (2019). Triplophysa wulongensis is located in a basal position of the cave-dwelling clade (Fig. 4). The K2P genetic distances show less differentiation between T. wulongensis and T. sanduensis (14.9%) than between T. wulongensis and its other congeners in this study. The K2P genetic distance (ranges from 14.9% to 24.9%) between the new species and some of the other species of Triplophysa based on cytb markers is consistent with species-level divergences in other fish taxa (Ward et al. 2005; Wang et al. 2016; Wu et al. 2020).

Figure 4. 

Phylogeny of some species of Triplophysa and two outgroup species based on maximum likelihood (ML) and Bayesian inference (BI) methods using mitochondrial cytb gene sequences. The ML bootstrap values and BI posterior probabilities are shown at the nodes

The presence or absence of the secondary sexual characteristics is important for the generic diagnosis of loaches (Bănărescu and Nalbant 1968; Zhu 1989). The presence of tubercles on the pectoral fin can be considered as an autapomorphy and is the single diagnostic character of Triplophysa (Prokofiev 2010). Nevertheless, according to Liang and Zhou (2019), some cave-dwelling species of Triplophysa, e.g. T. nasobarbatula and T. zhenfengensis, have lost secondary sexual characteristics. Sexual dimorphism was not evident in the type series of T. wulongensis, but the phylogenetic analysis confirmed the generic classification.

The majority of the cave-dwelling species of Triplophysa were described from karst caves and subterranean streams in the Pearl river basin and the upper Yangtze river basin, with an additional two species (T. erythraea and T. xiangxiensis) reported from the Yuanjiang river drainage (a tributary of the middle Yangtze River) and a single species (T. rosa) described from the Wujiang river drainage (Lan et al. 2013; Liu et al. 2017; Wu et al. 2018b; Chen and Peng 2019; Huang et al. 2019). In terms of morphology, T. wulongensis is distinguished from the co-occurring T. rosa by the presence of eyes (vs absence), 8 or 9 branched pectoral-fin rays (vs 12), 18 branched caudal-fin rays (vs 14), a pectoral fin length that is 15.6–18.4% that of the SL (vs 26.6%), and a body with irregular brown blotches (vs pale blotches).

The rate of discovery of new cave-dwelling species of Triplophysa has increased in recent years (Yang et al. 2016; Li et al. 2017a, b, 2018; Liu et al. 2017; Wu et al. 2018a, b; Chen and Peng 2019; Huang et al. 2019), while a taxonomic revision of these species is lacking. Hence, further systematic and phylogenetic study based on both morphometric and molecular approaches is needed.

Key to the cave-dwelling species of Triplophysa

1 Eyes normal 2
Eyes reduced or absent 16
2 Scales absent 3
Body covered by scales 8
3 Tip of pelvic fin reaching anus, outer gill rakers on first gill arch absent T. longliensis
Tip of pelvic fin not reaching anus; outer gill rakers on first gill arch present 4
4 Posterior chamber of air bladder developed; anterior nostril not elongate to barbel-like T. tianxingensis
Posterior chamber of air bladder degenerated; anterior nostril elongate to barbel-like 5
5 Dorsal-fin origin closer to caudal-fin base than to snout tip T. wulongensis sp. nov.
Dorsal-fin origin closer to snout tip than to caudal-fin base 6
6 Dorsal-fin origin opposite vertical line trough pelvic-fin origin T. nanpanjiangensis
Dorsal-fin origin anterior to vertical line trough pelvic fin origin 7
7 Caudal fin deep forked with 11–13 branched fin rays T. baotianensis
Caudal fin slightly forked with 14 branched fin rays T. xiangshuingensis
8 Processus dentiformis present in upper jaw T. zhenfengensis
Processus dentiformis absent in upper jaw 9
9 Posterior chamber of air bladder developed T. guizhouensis
Posterior chamber of air bladder degenerated 10
10 Tip of depressed pelvic fin exceeding anus 11
Tip of depressed pelvic fin not reaching anus 13
11 Anterior nostril not elongate to barbel-like; branched dorsal-fin rays 10 T. flavicorpus
Anterior nostril elongate to barbel-like; branched dorsal-fin rays 8 12
12 Tip of pectoral fin extending beyond pelvic-fin origin T. longipectoralis
Tip of pectoral fin not reaching pelvic-fin origin T. nasobarbatula
13 Branched dorsal-fin rays 7, branched anal-fin rays 7 T. yunnanensis
Branched dorsal-fin rays 8, branched anal-fin rays 5–6 14
14 Dorsal-fin origin opposite vertical line trough pelvic-fin origin T. nandanensis
Dorsal fin origin anterior to vertical line trough pelvic fin origin 15
15 Anterior nostril not elongate to barbel-like; branched caudal-fin rays 16 T. huapingensis
Anterior nostril elongate to barbel-like; branched dorsal-fin rays 17–18 T. sanduensis
16 Eyes reduced 17
Eyes absent 24
17 Body covered with scales 18
Scales absent, body smooth 19
18 Lateral line complete, branched anal-fin rays 6 T. luochengensis
Lateral line incomplete, branched anal-fin rays 5 T. lingyunensis
19 Lateral line incomplete; adipose keels present on upper or lower side of caudal peduncle T. langpingensis
Lateral line complete; adipose keels absent from caudal peduncle 20
20 Posterior chamber of air bladder developed T. xichouensis
Posterior chamber of air bladder degenerated 21
21 Tip of pelvic fin reaching anus 22
Tip of pelvic fin not reaching to anus 23
22 Tip of pectoral fin reaching to midway between pectoral-fin origin and pelvic-fin origin; Spots absent from body T. tianlinensis
Tip of pectoral fin reaching a vertical through dorsal-fin origin; spots present on body T. macrocephala
23 Dorsal-fin origin posterior to or at to vertical line trough pelvic-fin origin; branched caudal-fin rays 13 T. aluensis
Dorsal-fin origin anterior to vertical line trough pelvic-fin origin; branched caudal-fin rays 15–16 T. tianeensis
24 Lateral line absent T. huanjiangensis
Lateral line complete 25
25 Tip of pelvic-fin not reaching to anus 26
Tip of pelvic fin reaching to anus 28
26 Adipose keels present on upper or lower side of caudal peduncle T. posterodorsalus
Adipose keels absent from caudal peduncle 27
27 Branched dorsal-fin rays 8; branched caudal-fin rays 16 T. fengshanensis
Branched dorsal-fin rays 7; branched caudal-fin rays 14 T. shilinensis
28 Anterior nostril not elongate to barbel-like 29
Anterior nostril elongate to barbel-like 31
29 Lips developed, papillary process absent, branched caudal-fin rays 17 T. erythraea
Lips developed, papillary process present, branched caudal-fin rays 14–15 30
30 Branched dorsal fin rays 8; branched pectoral-fin rays 11 T. maolanensis
Branched dorsal-fin rays 7; branched pectoral-fin rays 7–9 T. qiubeiensis
31 Distal margin of dorsal fin truncate; branched dorsal-fin rays 7–8; branched pectoral-fin rays 9–11; branched pelvic-fin rays 6 32
Distal margin of dorsal-fin concave; branched dorsal-fin rays 9; branched pectoral-fin rays 12; branched pelvic-fin rays 7 T. rosa
32 Snout blunt; tip of pectoral fin not reaching vertical level of dorsal fin origin; tip of caudal-fin lobes pointed; branched caudal-fin rays 14–15 33
Snout rectangle-like; tip of pectoral fin reaching a vertical through dorsal-fin origin; tip of caudal-fin lobe sharp; branched caudal-fin rays 16 T. xiangxiensis
33 Cephalic lateral-line canals with 5 supraorbital and 7 preoperculo-mandibular pores T. gejiuensis
Cephalic lateral-line canals with 8 supraorbital and 12–13 preoperculo-mandibular pores T. anshuiensis

Acknowledgements

We are indebted to Ms Ni Liu for her help with the specimen collections. This work was supported by grant from the National Natural Science Foundation of China (31872204).

References

  • Bănărescu P, Nalbant T (1968) Cobitidae (Pisces, Cypriniformes) collected by the German India Expedition. Mitteilungenaus dem Hamburgischen Zoologischen Museum und Institut 65: 327–351.
  • Huang TF, Zhang PL, Huang XL, Wu T, Gong XY, Zhang YX, Peng QZ, Liu ZX (2019) A new cave-dwelling blind loach, Triplophysa erythraea sp. nov. (Cypriniformes: Nemacheilidae), from Hunan Province, China. Zoological Research 40(4): 331–336. https://doi.org/10.24272/j.issn.2095-8137.2019.049
  • Kottelat M (2012) Conspectus cobitidum: an inventory of the loaches of the world (Teleostei: Cypriniformes: Cobitoidei). The Raffles Bulletin of Zoology 26: 1–199.
  • Kottelat M, Freyhof J (2007) Handbook of European Freshwater Fishes. Kottelat, Cornol & Freyhof, Berlin, 646 pp.
  • Kumar S, Stecher G, Tamura K (2016) MEGA7: Molecular Evolutionary Genetics Analysis version 7.0 for bigger datasets. Molecular Biology and Evolution 33(7): 1870–1874. https://doi.org/10.1093/molbev/msw054
  • Lan JH, Gan X, Wu TJ, Yang J (2013) Cave Fishes of Guangxi, China. Science Press, Beijing, 266 pp. [In Chinese]
  • Li ChQ, Liu T, Li R, Li WX (2018) A new cave species of genus Triplophysa from Guizhou Province, China. Journal of Jishou University (Natural Science Edition) 39(4): 60–63. [in Chinese]
  • Li J, Lan JH, Chen XY, Du LN (2017a) Description of Triplophysa luochengensis sp. nov. (Teleostei: Nemacheilidae) from a karst cave in Guangxi, China. Journal of Fish Biology 91(4): 1009–1017. https://doi.org/10.1111/jfb.13364
  • Li J, Li XH, Lan JH, Du LN (2017b) A new troglobitic loach Triplophysa tianlinensis (Teleostei: Nemacheilidae) from Guangxi, China. Ichthyological Research 64(3): 295–300. https://doi.org/10.1007/s10228-016-0565-0
  • Li WX, Ran JCh, Chen HM (2006) A new species of Paracobitis from Guizhou, China. Journal of Zhanjiang Ocean University 26(4): 1–2. [in Chinese]
  • Liang J, Zhou J (2019) The disappearance of male secondary sexual characteristics in the typical cave species in Triplophysa. Transylvanian Review of Systematical and Ecological Research 21(1): 57–68. https://doi.org/10.2478/trser-2019-0005
  • Liu SW, Pan XF, Yang JX, Chen XY (2017) A new cave-dwelling loach, Triplophysa xichouensis sp. nov. (Teleostei: Nemacheilidae) from Yunnan, China. Journal of Fish Biology 90(3): 834–846. https://doi.org/10.1111/jfb.13201
  • Rambaut A (2014) FigTree 1.4.2 software. Institute of Evolutionary Biology, University of Edinburgh, Edinburgh.
  • Rambaut A, Drummond AJ, Xie D, Baele G, Suchard MA (2018) Posterior summarization in Bayesian phylogenetics using Tracer 1.7. Systematic Biology 67(5): 901–904. https://doi.org/10.1093/sysbio/syy032
  • Ronquist F, Teslenko M, van der Mark P, Ayres D, Darling A, Höhna S, Larget B, Liu L, Huelsenbeck JP (2012) MrBayes 3.2: Efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61: 539–542. https://doi.org/10.1093/sysbio/sys029
  • Wang Y, Shen Y, Feng Ch, Zhao K, Song Zh, Zhang Y, Yang L, He Sh (2016) Mitogenomic perspectives on the origin of Tibetan loaches and their adaptation to high altitude. Scientific Reports 6: 29690. https://doi.org/10.1038/srep29690
  • Ward RD, Zemlak TS, Innes HB, Last RP, Hebert PDN (2005) DNA barcoding Australia’s fish species. Philosophical Transactions of the Royal Society of London – Series B Biological Sciences 360: 1847–1857. https://doi.org/10.1098/rstb.2005.1716
  • Wu H, Gu Q, Zhou Ch, Tang Y, Husemann M, Meng X, Zhang J, Nie G, Li X (2020) Molecular phylogeny and biogeography of Triplophysa stone loaches in the Central Chinese Mountains. Biological Journal of the Linnean Society 130(3): 563–577. https://doi.org/10.1093/biolinnean/blaa060
  • Wu TJ, Wei ML, Lan JH, Du LN (2018a) Triplophysa anshuiensis, a new species of blind loach from the Xijiang River, China (Teleostei, Nemacheilidae). ZooKeys 744: 67–77. https://doi.org/10.3897/zookeys.744.21742
  • Wu WJ, He AY, Yang JX, Du LN (2018b) Description of a new species of Triplophysa (Teleostei: Nemacheilidae) from Guizhou Province, China. Journal of Fish Biology 93(1): 88–94. https://doi.org/10.1111/jfb.13670
  • Xiao WH, Zhang YP, Liu HZ (2001) Molecular systematics of Xenocyprinae (Teleostei: Cyprinidae): taxonomy, biogeography, and coevolution of a special group restricted in East Asia. Molecular Phylogenetics and Evolution 18(2): 163–173. https://doi.org/10.1006/mpev.2000.0879
  • Yang GY, Yuan FX, Liao YM (1986) A new blind Cobitidae fish from the subterranean water in Xiangxi, China. Journal of Huazhong Agricultural University 5(3): 219–223. [In Chinese]
  • Yang HF, Li WX, Chen ZM (2016) A new cave species of the Genus Triplophysa from Yunnan, China. Zoological Research 37(5): 296–300.
  • Yang J, Wu TJ, Yang JX (2012) A new cave-dwelling loach, Triplophysa macrocephala (Teleostei: Cypriniformes: Balitoridae), from Guangxi, China. Environmental Biology of Fishes 93(2): 169–175. https://doi.org/10.1007/s10641-011-9901-4
  • Zhu SQ (1989) The loaches of the subfamily Nemacheilinae in China (Cypriniformes: Cobitidae). Jiangsu Science and Technology Publishing House, Nanjing, 150 pp.

Supplementary material

Supplementary material 1 

Table S1

Shijing Chen, Bakhtiyor Sheraliev, Lu Shu, Zuogang Peng

Data type: Specimen list

Explanation note: Material examined of Triplophysa species from China.

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
Download file (25.95 kb)
login to comment