Research Article |
Corresponding author: Jie-xin Zou ( jxzou@ncu.edu.cn ) Academic editor: Sammy De Grave
© 2019 Song-bo Wang, Xian-min Zhou, Jie-xin Zou.
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:
Wang S-b, Zhou X-m, Zou J-x (2019) A new species of freshwater crab of the genus Mediapotamon Türkay & Dai, 1997 (Crustacea, Decapoda, Brachyura, Potamidae) from Guizhou, China. ZooKeys 873: 9-23. https://doi.org/10.3897/zookeys.873.36702
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A new species of Mediapotamon Türkay & Dai, 1997 from a karst system in southwest China is described. The new species can be separated from congeners by the combination of a sharp and distinct epibranchial tooth, the anterolateral region lined with few scattered granules, the terminal segment of the male first gonopod distinctly bent with a constant diameter, and the position of the female vulvae. Mitochondrial 16S rDNA genetic data was used to investigate the systematic position of the new species, which is supported as a new taxon.
freshwater crab, Mediapotamon liboense, systematics, taxonomy, 16S rDNA
China has the highest number of freshwater crab species in the world, with more than 300 species (
Specimens were collected from Banzhai Hill, Yaozhai village (25.2128°N, 108.0041°E), Dongtang town, Lino County, Qiannan Buyei and Miao Autonomous Prefecture, Guizhou Province; preserved in 95% ethanol; and deposited at the Department of Parasitology of the Medical College of Nanchang University, Jiangxi, China (NCU MCP). Comparative materials were deposited at the Sun Yat-sen Museum of Biology, Sun Yat-sen University, Guangzhou, China (SYSBM) and the Institute of Zoology, Chinese Academy of Sciences, Beijing, China (
Pereiopod muscle tissue was extracted from specimens of the new species with a DP1902 Tissue Kit (BioTeke Inc., Beijing). The mitochondrial 16S rDNA gene was obtained by PCR amplification with the primers 1471 (5’-CCTGTTTANCAAAAACAT-3’) and 1472 (5’-AGATAGAAACCAACCTGG-3’) (Shih et al. 2004). The PCR extension procedure is as follows: denaturation for 50 s at 94 °C, 33 cycles of annealing for 40 s at 52 °C and extension for 1 min at 72 °C and a final extension for 10 min at 72 °C. The PCR products were sequenced on an ABI 3730 automatic sequencer.
For molecular data analysis, the mitochondrial 16S rDNA from 52 species in 41 genera was used to construct a phylogenetic tree (Table
The 16S rDNA of 52 species from 41 genera of the family Potamidae from Asia. All sequences retrieved from GenBank except for the new species described herein.
Species | Museum catalogue number | Locality | GenBank number |
Amamiku amamense (Minei, 1973) |
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Amami, the Ryukyus | AB428457 |
Aparapotamon grahami (Rathbun, 1929) |
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Yunnan, China | AB428489 |
Apotamonautes hainanensis (Parisi, 1916) |
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Hainan, China | AB428459 |
Beccumon jarujini (Ng & Naiyanetr, 1993) |
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Chiangma, Thailand | AB428479 |
Candidiopotamon rathbunae (De Man, 1914) |
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Nantou, Taiwan | AB208598 |
Chinapotamon glabrum (Dai, Song, Li & Liang, 1980) |
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Guangxi, China | AB428451 |
Chinapotamon maolanense Zou, Bai & Zhou, 2018 | NCU MCP 196101 | Guizhou, China | 11280060 |
Cryptopotamon anacoluthon (Kemp, 1918) |
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Hong Kong | AB428453 |
Daipotamon minos Ng & Trontelj, 1996 |
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Guizhou, China | LC198524 |
Demanietta renongensis (Rathbun, 1905) |
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Ranong, Thailand | AB428475 |
Diyutamon cereum Huang, Shih & Ng, 2017 | SYSBM | Guizhou, China | LC198520 |
Eosamon boonyaratae (Naiyanetr, 1987) |
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Trat, Thailand | AB428487 |
Eosamon smithianum (Kemp, 1923) |
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Chantaburi, Thailand | AB428486B428486 |
Eosamon yotdomense (Naiyanetr, 1984) |
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Ubon Ratchathani, Thailand | AB428485 |
Esanpotamon namsom Naiyanetr & Ng, 1997 |
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Udon Thani, Thailand | AB428463 |
Flabellamon sp. |
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Mae Sot, Thailand | AB428472 |
Geothelphusa albogilva Shy, Ng & Yu, 1994 |
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Pingtung, Taiwan | AB127366 |
Geothelphusa marginata fulva Naruse, Shokita & Shy, 2004 |
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Iriomote, the Ryukyus | AB428456 |
Geothelphusa olea Shy, Ng & Yu, 1994 |
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Taichung, Taiwan | AB428455 |
Hainanpotamon fuchengense Dai, 1995 |
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Hainan, China | AB428461 |
Huananpotamon angulatum (Dai & Lin, 1979) |
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Fujian, China | AB428454 |
Indochinamon ou (Yeo & Ng, 1998) |
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Phongsali, Laos | AB428481 |
Indochinamon tannanti (Rathbun, 1904) |
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Yunnan, China | AB428482 |
Johora johorensis (Roux, 1936) |
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Gunung Pulai, Johor, Malaysia | AB290620 |
Johora murphyi Ng, 1986 |
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Kota Tinggi, Johor, Malaysia | AB290621 |
Kanpotamon duangkhaei Ng & Naiyanetr, 1993 |
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Kanchanaburi, Thailand | AB428471 |
Kukrimon cucphuongense (Dang, 1975) |
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Ninh Binh, Vietnam | AB428483 |
Longpotamon baiyanense Ng & Dai, 1997 |
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Hunan, China | AB428470 |
Longpotamon planum Dai, 1992 |
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Anhui, China | AB428469 |
Mediapotamon leishanense Dai, 1995 | SYSBM001094 | Guizhou, China | LC155164 |
Mediapotamon liboense sp. nov. | NCU MCP 343004 | Guizhou, China | MK820377 |
Mediapotamon liboense sp. nov. | NCU MCP 343008 | Guizhou, China | MK820376 |
Mediapotamon sp. nov., leg. Chao Huang | SYSBM001259 | Guizhou, China | LC155165 |
Megacephalomon kittikooni (Yeo & Naiyanetr, 1999) |
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Xieng Khuang, Laos | AB428462 |
Mindoron balssi (Bott, 1968) |
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Mindoro, the Philippines | AB428464 |
Minpotamon nasicum (Dai & Chen, 1979) |
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Fujian, China | AB428450 |
Nanhaipotamon formosensis (Parisi, 1916) |
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Tainan, Taiwan | AB212867 |
Nanhaipotamon nanriense Dai, 1997 |
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Fujian, China | AB212868 |
Neotiwaripotamon jianfengense Dai & Naiyanetr, 1994 |
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Hainan, China | AB428460 |
Ovitamon artifrons (Bürger, 1894) |
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Luzon, the Philippines | AB428466 |
Parapotamon spinescens (Calman, 1905) | NCUDP | Yunnan, China | AB428467 |
Pararanguna semilunatum Dai & Chen, 1985 |
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Yunnan, China | AB428490 |
Potamiscus yiwuensis Dai & Cai, 1998 |
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Yunnan, China | AB428476 |
Potamiscus yongshengense Dai & Chen, 1985 | NNU150951 | Yunnan, China | KY963597 |
Pudaengon sakonnakorn Ng & Naiyanetr, 1995 |
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Thailand | AB428484 |
Pupamon nayung (Naiyanetr, 1993) |
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Udon Thani, Thailand | AB428477 |
Ryukyum yaeyamense (Minei, 1973) |
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Iriomote, the Ryukyus | AB428458 |
Shanphusa curtobates (Kemp, 1918) |
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Taunggyi, Shan State, Myanmar | AB428478 |
Socotrapotamon nojidensis Apel & Brandis, 2000 |
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Socotra, Yemen | AB428493 |
Tenuipotamon huaningense Dai & Bo, 1994 |
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Yunnan, China | AB428491 |
Thaiphusa sp. |
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Thailand | AB428474 |
Tomaculamon pygmaeus Yeo & Ng, 1997 |
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Phitsanulok, Thailand | AB428473 |
Trichopotamon daliense Dai & Chen, 1985 |
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Yunnan, China | AB428492 |
Yarepotamon gracilipa (Dai, Song, Li & Liang, 1980) |
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Guangxi, China | AB428452 |
China, Guizhou Province: Qiannan Bouyei and Miao Autonomous Prefecture, Lino County, Dongtang Town, Yaozhai Village, Banzhai Hill, 25.2128°N, 108.0041°E, under rock in small hill stream.
Holotype male, with gonopods in a separate microvial. Original label: “China, Guizhou Province: Qiannan Bouyei and Miao Autonomous Prefecture, Lino County, Dongtang Town, Yaozhai Village, Banzhai Hill, 25.2128°N, 108.0041°E, 10 Oct. 2010, Xian-min Zhou”, “NCU MCP 343001”. Paratypes, male, same collection data as for holotype, “NCU MCP 343002”; female, same collection data as for holotype, “NCU MCP 343003”.
Holotype. CHINA • ♂, NCU MCP 343001, 24.2 × 19.6 mm, Guizhou Province, Qiannan Bouyei and Miao Autonomous Prefecture, Lino County, Dongtang Town, Yaozhai Village, Banzhai Hill, under rock in small hill stream, catch by hand, 10 Oct 2010, Xian-min Zhou leg.
Paratypes. ♂, NCU MCP 343002,19.4 × 15.6 mm • ♀, NCU MCP 343003, 23.4 × 19.0 mm, same collection data as for holotype.
♂, NCU MCP 343004, 30.9 × 24.7 mm • 4 ♀♀; NCU MCP 343005, 21.5 × 16.8mm; NCU MCP 343006, 19.2 × 14.6 mm; NCU MCP 343007, 25.0 × 20.0 mm; NCU MCP 343008, 20.0 × 15.8 mm; same collection data as for holotype.
Mediapotamon angustipedum (Dai & Song, 1982): 2 ♂♂;
Carapace trapezoidal, regions indistinct, dorsal surface flat, epigastric cristae indistinct, postorbital cristae convex, cervical groove indistinct, H-shaped groove inconspicuous (Figs
Carapace: outline trapezoidal, width 1.2–1.3 × length (n = 8); dorsal surface flat with numerous pits, anterolateral region wrinkled (Figs
Third maxilliped: exopod reaching proximal 1/3 of merus length, with slender flagellum extending equal to width of merus (Figs
Chelipeds (pereiopod 1): slightly unequal (Fig.
Mediapotamon liboense sp. nov. Holotype male (24.2 × 19.6 mm) (NCU MCP 343001). A ventral view of the left G1 B dorsal view of the left G1 C ventral view of the left G2 D ventral view of the terminal segment of left G1 E dorsal view of the terminal segment of left G1 F mesial view of the terminal segment of left G1. Scale bars: 1 mm (A–F).
Ambulatory legs (pereiopods 2–5): slender; pereiopod 3 merus 0.5 × carapace length in males (n = 3), 0.4 × carapace length in females (n = 5) (Figs
Male thoracic sternum: flat and covered with pits; sternites 2-4 broad, width ca. 2 × length; sternites 2 very broad triangular with sharp apex; suture between sternites 2/3 transverse, clear; sternites 3/4 fused but with slight oblique demarcation superficially (Fig.
Male pleon: narrow triangular (Fig.
G1: slender (Figs
Female vulva: large, not reaching sternites 5/6 in situ, with the opening outward and the outer membrane extending outward (Fig.
The species is named after the type locality, Libo County, Qiannan Bouyei and Miao Autonomous Prefecture, Guizhou Province.
The new species is presently known only from the type locality: Libo County, Qiannan Bouyei and Miao Autonomous Prefecture, Guizhou Province.
The new species fits the characteristics of Mediapotamon Türkay & Dai, 1997, viz., carapace intermediate or small in size (15–20 mm), surface smooth without a conspicuous bulge or depression, anterolateral margin lined with granules, male telson triangular, and G1 slender without any projection and reaching the pleonal locking tubercle in situ (
We used the mitochondrial 16S rDNA gene sequence for phylogenetic analyses, and 52 species from 41 potamid genera were included (Table
A Bayesian inference (BI) tree based on 16S rDNA with the sequences and accession numbers from
Despite the new species clustering with congeners and Daipotamon in the larger clade, the genetic distance suggests that the congeners are closer, while Daipotamon is farther away. For the habitat, Daipotamon lives in limestone formations and collected from one of karst caves and was determined as a karst species (
Differences between Mediapotamon liboense sp. nov., M. angustipedum (Dai & Song, 1982), M. leishanense Dai, 1995 and Daipotamon minos, Ng & Trontelj, 1996.
Character/ Species | M. liboense sp. nov. | M. angustipedum | M. leishanense | Daipotamon minos |
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Carapace | Flat, cervical groove indistinct | Swollen, cervical groove indistinct | Flat, cervical groove distinct | Slightly swollen, cervical groove distinct |
Epibranchial tooth | Sharp, distinct | Sharp, distinct | Blunt, indistinct | Blunt, indistinct |
Anterolateral margin | Lined with scattered granules | Lined with numerous inseparable granules | Lined with numerous inseparable granules | Lined with numerous inseparable granules |
Shape of male telson | Narrow triangular | Broad triangular | Broad triangular | Tongue-shape |
G1 in situ | Reaching pleonal locking tubercle | Reaching pleonal locking tubercle | Reaching pleonal locking tubercle | Not reaching pleonal locking tubercle |
Shape of G1 | Slender, terminal segment obviously bent with constant diameter | Very slender, terminal segment straight and gradually narrowing | Very slender, terminal segment obviously bent and gradually narrowing | Stout, terminal segment slightly bent with constant diameter |
Female vulvae | Large-sized, not reaching sternites 5/6 in situ | Medium-sized, reaching sternites 5/6 in situ | Large-sized, reaching sternites 5/6 in situ | Medium-sized, not reaching sternites 5/6 in situ |
Before our study, only three new species, namely Diyutamon cereum, Qianguimon elongatum, and Chinapotamon maolanense, collected in Guizhou had been published in the past 20 years (
The present study is supported by the National Sharing Service Platform for Parasite Resources (TDRC-22), the National Natural Science Foundation of China (No. 31560179, 31460156), the Natural Science Foundation of Jiangxi Province (No. 20171BAB205108), Nanchang University College Students’ Innovation and Entrepreneurship Training Program (No. 2018388). Thanks are due to Chao Huang, who also collected a specimen, for providing several original materials for the images and for appraising the new species when we identified it. We also thank Ya-Nan Zhang and Meng-Jun Zhao for their help in the molecular work and Xin-Nan Jia and Shu-Xin Xu for their help in constructing the phylogenetic tree.