Friday, October 3, 2014

[Crustacea • 2014] Geothelphusa cilan • Description of A New Montane Freshwater Crab (Crustacea: Potamidae) from northern Taiwan


FIGURE 2. Geothelphusa cilan sp. nov.
A, B,
dorsal and frontal views of the holotype (NCHUZOOL 13617);
D–G, live coloration of the male, dorsal view (D, E) and frontal view (F, G); D, F, NCHUZOOL 13618 (CW 20.6 mm); G, NCHUZOOL 13620 (CW 15.5 mm);
H, habitat in a montane creek in the headstream of Danshuei River, Jianshih, Hsinchu County.

Abstract
A new freshwater crab is described from a montane area in northern Taiwan based on morphological characters and molecular evidence. Geothelphusa cilan sp. nov., from the Cilan Forest, situated on the boundary of Hsinchu and Yilan (= Ilan) counties, is close to G. monticola Shy, Ng & Yu, 1994, and G. takuan Shy, Ng & Yu, 1994, but can be distinguished by its male first gonopod (G1) and the ratio of thoracic sternites. Molecular evidence from mitochondrial cytochrome oxidase subunit I (COI) also supports the identity of the new species.

Keywords: Potamidae, freshwater crab, new species, Taiwan, DNA, COI


Taxonomy
Family Potamidae Ortmann, 1896
Subfamily Potamiscinae Ortmann, 1896 (sensu Yeo & Ng 2003)

Geothelphusa 
Stimpson, 1858

Geothelphusa cilan sp. nov.

FIGURE 2. Geothelphusa cilan sp. nov.
A, dorsal views of the holotype (NCHUZOOL 13617);
D–G, live coloration of the male, dorsal view (D) and frontal view (F, G); D, F, NCHUZOOL 13618 (CW 20.6 mm); G, NCHUZOOL 13620 (CW 15.5 mm);
H, habitat in a montane creek in the headstream of Danshuei River, Jianshih, Hsinchu County.

Etymology. The species is named for the type locality, the Cilan Forest, in northern Taiwan. The name is used as a noun in apposition.

Coloration. Carapace and ambulatory legs grayish brown, mottled with dark brown spots; chelae orange-red, with dark brown spots; tip and inner edge of fingers white (Fig. 2D–G).

Ecological notes. The specimens were collected from the headstream of Danshuei River (Fig. 2H) near the boundary of Hsinchu and Yilan counties, near Yuanyang Lake Nature Reserve, with an altitude about 2000 m. The mean monthly water temperatures were 10.3–14.6°C during April to December, 2012 (mean 12.6°C) for the adjacent Yuanyang Lake, with the same drainage


Shy, Jhy-yun, Hsi-te Shih & Jean-jay Mao. 2014. Description of A New Montane Freshwater Crab (Crustacea: Potamidae: Geothelphusa) from northern Taiwan.
Zootaxa. 3869(5): 565–572. DOI: 10.11646/zootaxa.3869.5.6.
http://mapress.com/zootaxa/2014/f/zt03869p572.pdf

Shy, J.-Y., Ng, P.K.L. & Yu, H.-P. 1994. Crabs of the genus Geothelphusa Stimpson, 1858 (Crustacea: Decapoda: Brachyura: Potamidae) from Taiwan, with descriptions of 25 new species. The Raffles Bulletin of Zoology. 42, 781–846. http://rmbr.nus.edu.sg/rbz/biblio/42/42rbz781-846.pdf