Research Article |
Corresponding author: Li-Na Du ( duln04@mail.kiz.ac.cn ) Academic editor: Nina Bogutskaya
© 2018 Tie-Jun Wu, Mu-Lan Wei, Jia-Hu Lan, Li-Na Du.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Wu T-J, Wei M-L, Lan J-H, Du L-N (2018) 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
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A new cave-dwelling fish, Triplophysa anshuiensis, is described here based on specimens collected from a karst cave in Guangxi Zhuang Autonomous Region, China, interconnected with the Hongshui River system, a tributary of the Xijiang River in the Pearl River (Zhu Jiang) Drainage. The species can be distinguished from its congeners by a combination of morphological characters. A key to the cave-dwelling species of Triplophysa in the Xijiang River is provided.
cave fish, Guangxi, new species, Triplophysa
Triplophysa is an ecologically important and taxonomically challenging genus, distributed in lakes, rivers, and streams of the Qinghai-Tibet Plateau and adjacent region. The genus is diagnosed by a marked sexual dimorphism. In males the dorsal surface of the outer pectoral-fin rays are thickened, broadened, and covered by breeding tubercles; breeding tubercles are also present on the sides of the head, extending from the eye almost to the insertion of the maxillary barbels. Even though Barbatula species share the same sexual dimorphism, Triplophysa can be distinguished by close together nostrils in contrast to widely separated nostrils in Barbatula (
The distribution area of the genus extends westward to the Aral Sea Basin and interior drainages of Baluchistan and north-westward to western Mongolia and Republic of Tuva in Russia (
Specimens were preserved in 8 % formalin and are maintained at the Kunming Natural History Museum of Zoology, Kunming Institute of Zoology (
Data on T. huanjiangensis, T. fengshanensis, and T. dongganensis are cited from
Holotype. Kunming Natural History Museum of Zoology, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, KIZ2012005747, 65.2 mm standard length, Anshui Village, Lingyun County, Guangxi Zhuang Autonomous Region, China; 24.3632N, 106.7412E, Altitude 719 m; collected by J. H. Lan, 12 May 2012. Paratypes. Kunming Natural History Museum of Zoology,
Triplophysa anshuiensis can be distinguished from all species of Triplophysa by the following combination of characters: eyes absent, gill rakers absent in outer row and eight gill rakers in inner row on first gill arch, 14 branched caudal-fin rays, body scaleless, tips of depressed pectoral fins not reaching pelvic-fin origin, 12–13 preoperculo-mandibular pores, lateral line complete, posterior chamber of air bladder developed.
Morphometric data of type specimens of Triplophysa anshuiensis are given in Table
Measurements | Paratype | Holotype |
---|---|---|
2012005746 | 201005747 | |
Standard length | 68.5 | 65.2 |
Lateral head length | 14.5 | 13.8 |
Percent of SL | ||
Body depth | 15.7 | 12.2 |
Lateral head length | 21.1 | 21.1 |
Predorsal length | 52.6 | 47.5 |
Prepelvic length | 55.1 | 52.0 |
Preanal length | 79.2 | 72.5 |
Preanus length | 71.4 | 66.9 |
Caudal-peduncle length | 15.1 | 14.6 |
Caudal-peduncle depth | 9.0 | 9.8 |
Percent of HL | ||
Maximum head depth | 50.7 | 47.7 |
Maximum head width | 53.1 | 52.0 |
Pectoral fin length/Pt-Pl | 66.4 | 59.8 |
Pelvic fin length/Pl-A | 77.2 | 63.6 |
CPD/CPL | 59.2 | 67.3 |
Body elongated, slightly compressed anteriorly, more strongly compressed posteriorly. Deepest point of body in front of dorsal-fin origin, body depth 12–16% of SL. Head compressed, maximum width greater than depth. Anterior and posterior nostrils adjacent, anterior nostril in short tube with elongated barbel-like tip, tip of nostril barbel reaching posterior margin of posterior nostrils. Eyes absent. Mouth inferior, mouth corner situated below anterior nostril. Lips thick with shallow furrows; lower lip with a “V” type median notch. Upper and lower jaw arched, processus dentiformis on upper jaw absent and no corresponding notch on lower jaw. Three pairs of barbels; inner rostral barbel 50–54 % of lateral head length; outer rostral barbel 20–26 % of lateral head length; maxillary barbel 36–39 % of lateral head length. Body scaleless. Intestine straight. Posterior chamber of air bladder developed, reaching dorsal-fin origin (Fig.
Dorsal fin distally truncate, origin anterior to pelvic-fin insertion, situated slightly anterior to midpoint between tip of snout and caudal-fin base; first branched ray longest, reaching anus when adpressed vertically. Anal fin distally truncate. Pectoral fins moderately developed, 60–67 % of distance between pectoral and pelvic fins. Tip of depressed pelvic fin reaching anus. Anus short distance from anal-fin origin. Caudal fin forked, tips pointed.
Coloration. Fixation in 8 % formalin, body yellowish. Black pigments irregularly present on dorsum of body.
Sexual dimorphism. No sexual dimorphism was observed in the two specimens.
A karst cave in Anshui Village, Lingyun County, Guangxi Zhuang Autonomous Region, China, whichis interconnected with the Hongshui River system, a tributary of the Xijiang River in the Pearl River (Zhu Jiang) Drainage.
An underground stream was found about 40 m from and 10 m below the entrance to a cave. Triplophysa anshuiensis inhabits pools in which the substratum is mud and cobblestones (Fig.
The specific name, anshuiensis, is derived from the village Anshui, the type locality of the species.
Thirteen Triplophysa species have been recorded in karst caves and subterranean streams in the Guangxi Zhuang Autonomous Region (
In the group of Guangxi species with completely reduced eyes, T. anshuiensis is similar to T. lihuensis, T. huanjiangensis, T. fengshanensis, and T. dongganensis in having no scales on the whole body. The new species can be distinguished from T. lihuensis and T. huanjiangensis by 8 gill rakers in inner row on first gill arch (vs. 10–13 in T. lihuensis and T. huanjiangensis, whereas unknown in T. dongganensis and T. fengshanensis), from T. fengshanensis by 14 branched caudal-fin rays (vs. 16), and caudal peduncle depth 6.6–6.9 times in standard length (vs. 5.0–5.3), and from T. dongganensis by caudal peduncle depth 10.2–11.2 times in standard length (vs. 11.4–16.9), and caudal peduncle depth 1.5–1.7 times in its length (vs. 1.8–2.9). In addition to the species of Triplophysa from Guangxi, there are ten more troglobitic Triplophysa species recorded in the Xijiang River, including T. aluensis, T. gejiuensis, T. longibarbata, T. nasobarbatula, T. qiubeiensis, T. shilinensis, T. xiangshuingensis, T. yunnanensis, and T. zhenfengensis (Chen 1992,
1 | Eyes normal | 2 |
– | Eyes reduced or absent | 10 |
2 | Body scaleless | 3 |
– | Body covered by scales | 4 |
3 | Fourteen branched caudal-fin rays | T. xiangshuingensis |
– | Sixteen branched caudal-fin rays | T. aluensis |
4 | Processus dentiformis present in upper jaw | T. zhenfengensis |
– | Processus dentiformis absent in upper jaw | 5 |
5 | Tip of pectoral fin exceeding pelvic fin origin | T. longipectoralis |
– | Tip of pectoral fin not reaching pelvic fin origin | 6 |
6 | Tip of depressed pelvic fin exceeding anus | T. flavicorpus |
– | Tip of depressed pelvic fin not reaching anus | 7 |
7 | Eye diameter / lateral head length < 10 % | T. yunnanensis |
– | Eye diameter / lateral head length > 10 % | 8 |
8 | Caudal peduncle length/depth 1.8–2.1 | T. nasobarbatula |
– | Caudal peduncle length/depth 1.2–1.7 | 9 |
9 | Pectoral fin length / PT-PL 58–69 % | T. huapingensis |
– | Pectoral fin length / PT-PL 78–82 % | T. nandanensis |
10 | Eyes reduced | 11 |
– | Eyes absent | 15 |
11 | Lateral line incomplete | T. langpingensis |
– | Lateral line complete | 12 |
12 | Body covered by scales | T. luochengensis |
– | Body scaleless | 13 |
13 | Nine gill rakers in inner row on the first gill arch… | T. macrocephala |
– | Ten–11 gill rakers in inner row on the first gill arch | 14 |
14 | Eight–9 branched pectoral-fin rays | T. tianeensis |
– | Ten branched pectoral-fin rays | T. tianlinensis |
15 | Lateral-line absent | 16 |
– | Lateral-line complete | 17 |
16 | Posterior chamber of air bladder developed | T. huanjiangensis |
– | Posterior chamber of air bladder reduced | T. lihuensis |
17 | Six branched dorsal-fin rays | T. shilinensis |
– | Seven branched dorsal-fin rays | 18 |
18 | Five branched pelvic-fin rays | T. qiubeiensis |
– | Seven branched pelvic-fin rays | 19 |
19 | Sixteen branched caudal-fin rays | T. fengshanensis |
– | Thirteen–15 branched caudal-fin rays | 20 |
20 | Caudal peduncle length/depth 3–3.1 | T. longibarbata |
– | Caudal peduncle length/depth less than 3 | 21 |
21 | Standard length/caudal peduncle depth more than 14 | T. dongganensis |
– | Standard length/ caudal peduncle depth less than 12 | 22 |
22 | Cephalic lateral-line canals with 8 supraorbital and 12–13 preoperculo-mandibular pores | T. anshuiensis sp. n. |
– | Cephalic lateral-line canals with 5 supraorbital and 7 preoperculo-mandibular pores | T. gejiuensis |
All specimens from Pearl River.
Triplophysa gejiuensis:
T. huapingensis:
T. macrocephala:
T. shilinensis:
T. tianeensis:
T. nandanensis:
T. longipectoralis:
T. lihuensis:
T. langpingensis: uncat. 3 ex, 44.7–70.9 mm SL, Langping County, Guangxi Zhuang Autonomous Region.
T. aluensis:
T. yunnanensis:
T. nasobarbatula:
The study was funded by the Special Funds for Young Scholars of Taxonomy of the Chinese Academy of Sciences (ZSBR-011), National Natural Science Foundation of China (31460556), and Guangxi Natural Science Foundation (2017GXNSFFA198010). We are grateful to Dr Christine Watts for polishing this manuscript before submission.