PlantaeDecapodaPotamidaeHuangChaoShihHsi-TeMaoSi YingYuebeipotamon calciatile, a new genus and new species of freshwater crab from southern China (Crustacea, Decapoda, Brachyura, Potamidae)Zookeys7920162016615617210.3897/zookeys.615.9964 Yuebeipotamon http://zoobank.org/BF003144-6BF4-43AD-8772-DDF577DD6F22 gen. n.Diagnosis.

Carapace subquadrate, with dorsal surface slightly convex, surface generally smooth, rugose on anterolateral regions (Fig. 2A); postorbital and epigastric cristae distinct, not confluent (Fig. 2A); external orbital angle sharply triangular, separated from anterolateral margin by a narrow gap (Fig. 2A, B); median lobe of posterior margin of epistome sharply triangular (Fig. 2B); third maxilliped with relatively broad ischium, exopod of third maxilliped reaches beyond anterior edge of ischium, with short flagellum (Fig. 3D); male abdomen triangular, with short triangular telson (Fig. 2C); G1 generally slender, terminal segment large, elongated, with subbasal flap (Figs 2D, 3B, C); basal segment of G2 subquadrate (Fig. 3A).

Type species.

Yuebeipotamon calciatile sp. n., by monotypy.

Etymology.

The genus name is derived from the Chinese spelling system “Yue Bei”, which means northern Guangdong, for the locality of this genus. The suffix “Potamon” refers to the type genus of the family Potamidae, Potamon. Gender of genus neuter.

Remarks.

Although Sinopotamon, Longpotamon, Tenuilapotamon, and Yuebeipotamon are superficially similar in carapace features, Yuebeipotamon can easily be distinguished from by a number of characters (Table 1).

Morphological differences among Yuebeipotamon gen. n., Tenuilapotamon Dai, Song, Li, Chen, Wang & Hu, 1984, Sinopotamon Bott, 1967, and Longpotamon Shih, Huang & Ng, 2016.

Character Yuebeipotamon Tenuilapotamon Sinopotamon Longpotamon
Epibranchial teethdistinct, sharp (Fig. 2A)indistinct, granular (cf. Dai 1999: pl. 29)varied (cf. Dai 1999: pl. 17)varied (cf. Zou et. al. 2008: fig. 1)
Ambulatory legsslender (Fig. 2A)slender (cf. Dai 1999: pl. 29)stout (cf. Dai 1999: pl. 17)stout (cf. Zou et al. 2008: fig. 1)
Size of triangular structure of male thoracic sternites 1, 2relatively large (Fig. 4C)relatively small (unpublished data)relatively small (cf. Shih et al. 2016: fig. 3C)relatively small (cf. Shih et al. 2016: fig. 6C)
Male telsonrelatively short, triangular (Fig. 2C)relatively long, subtriangular (cf. Dai 1999: fig. 225)relatively long, nipple shaped (cf. Dai 1999: fig. 139)relatively long, subtriangular (cf. Zou et al. 2008: fig. 2)
G1 long, reaching beyond tubercle of abdominal lock (Fig. 2D)short, not reaching tubercle of abdominal lock (cf. Dai 1999: fig. 225)long, reaching beyond tubercle of abdominal lock (cf. Dai 1999: fig. 139)short, not reaching tubercle of abdominal lock (cf. Dai 1999: fig. 137)
Terminal segment of G1lo006Ecxcg, with subbasal flap (Fig. 3C)short, without subbasal flap (cf. Dai 1999: fig. 225)short, without subbasal flap (cf. Dai 1999: fig. 139)short, without subbasal flap (cf. Zou et al. 2008: fig. 2)
Comparative material from China.

Sinopotamon kwanhsiense Tai & Sung, 1975: 1 ♂ (45.3 × 36.0 mm), IZCAS CB7659, Chengdu, Sichuan, 1984. Sinopotamon pingshanense Dai & Liu, 1994: 1 ♂ (45.2 × 34.3 mm), IZCAS CB8278, Muchuan, Sichuan, Oct. 1986. Longpotamon anyuanense (Dai, Zhou & Peng, 1995): 1 ♂ (45.7 × 39.1 mm) (SYSBM 001080), Shaoguan City, Guangdong, Apr. 2013; Longpotamon chekiangense (Tai & Sung, 1975): 1 ♂ (32.0 × 26.1 mm) (SYSBM 001079), Lucheng District, Wenzhou City, Zhejiang, Mar. 2013; Longpotamon fukienense (Dai & Chen, 1979): 1 ♂ (45.7 × 39.1 mm) (SYSBM 001054), Fuqing City, Fujian, May 2013. Tenuilapotamon joshuiense (Dai, Song, He, Cao, Xu & Zhong, 1975): 1 ♂ (23.6 × 19.3 mm) (SYSBM 001270), Lianyuan City, Hunan, Sep. 2013; 1 ♀ (23.7 × 19.4 mm) (SYSBM 001271), same data as above.

Yuebeipotamon calciatile gen. n., sp. n., male holotype (32.4 × 27.0 mm) (SYSBM 001294). A dorsal view B frontal view of carapace C ventral view showing anterior thoracic sternum and abdomen D ventral view showing sterno-abdominal cavity with right G1 in situ (left G1 removed).

Yuebeipotamon calciatile gen. n., sp. n., male holotype (32.4 × 27.0 mm) (SYSBM 001294). A left G2 B left G1 (ventral view) C terminal segment of G1 (ventral view) D left third maxilliped. Scale bar 1.0 mm.

Yuebeipotamon calciatile gen. n., sp. n., male holotype (32.4 × 27.0 mm) (SYSBM 001294). A left G1 (ventral view) B terminal segment of G1 (ventral view) C anterior thoracic sternum.

 DaiAY (1999) Fauna Sinica: ArthropodaCrustaceaMalacostracaDecapodaParathelphusidaePotamidae. Science Press, Beijing, China, 501 pp. [In Chinese with English summary] ZouJXNaruseTZhouXM (2008) On a new species of freshwater crab of the genus Sinopotamon (Decapoda, Brachyura, Potamidae) from Wuyi mountain, southeastern China. Crustaceana 81: 1381–1387. doi: 10.1163/156854008X361076 ShihHTHuangCNgPKL (2016) A re-appraisal of the widely-distributed freshwater crab genus Sinopotamon Bott, 1967, from China, with establishment of a new genus (Crustacea: Decapoda: Potamidae). Zootaxa 4138: 309–331. doi: 10.11646/zootaxa.4138.2.5