Friday, September 8, 2017

[Crustacea • 2017] Tiwaripotamon hamyen & T. xuanson • Two New Species of Freshwater Crabs of the Genus Tiwaripotamon Bott, 1970 (Decapoda, Brachyura, Potamidae) from northern Vietnam


Tiwaripotamon hamyen 
Do, Nguyen & Dang, 2017 

RAFFLES BULLETIN OF ZOOLOGY. 65 

Abstract

 Two new terrestrial crab species of the family Potamidae, Tiwaripotamon xuanson and T. hamyen, are described from northern Vietnam. Tiwaripotamon xuanson was collected from Xuan Son National Park, Thanh Son district, Phu Tho province, and T. hamyen was found in Binh Xa commune, Ham Yen district, Tuyen Quang province. They can be distinguished from other congeners by distinct carapace characteristics and gonopod 1 structures.

 Key words. Tiwaripotamon xuanson, Tiwaripotamon hamyen, taxonomy

Fig. 8. Tiwaripotamon hamyen, new species, with differences living colour in carapace and ambulatory legs.

TAXONOMY
Family Potamidae Ortmann, 1896
Subfamily Potamiscinae Ortmann, 1896 (sensu Yeo & Ng, 2004)

Genus Tiwaripotamon Bott, 1970
Type species: Geothelphusa annamensis Balss, 1914, by original designation


Tiwaripotamon xuanson, new species

Etymology. The new species is named after the type locality, Xuan Son National Park. The name is used as a noun in apposition. 

Live colouration. Carapace reddish, chela and ambulatory legs red. 

Ecological notes. This species inhabits limestone mountains far from water bodies, on the forest floor. One specimen was found in a fallen dead tree (Fig. 5). The other specimens were found in rock cavities and under leaf litter.


Tiwaripotamon hamyen, new species 

Etymology. The new species is named after the type locality, Ham Yen. The name is used as a noun in apposition. 

Live colouration. Carapace and chela milky to light gray, ambulatory legs vary from milky to light gray or purple mixed light orange (Fig. 8A–D).

Ecological notes. This species inhabits limestone mountains. Our observation of this species and other Tiwaripotamon species from Vietnam confirm that they have terrestrial habits. They were often found far from water sources like streams and ponds. We observed a female T. edostilus carrying juveniles walking on the forest floor not close to any water body. It means these juveniles did not develop in streams or ponds.


Van Tu Do, Tong Cuong Nguyen and Van Dong Dang. 2017. Two New Species of Freshwater Crabs of the Genus Tiwaripotamon Bott, 1970 (Crustacea, Decapoda, Brachyura, Potamidae) from northern Vietnam. RAFFLES BULLETIN OF ZOOLOGY65; 455–465. lkcnhm.nus.edu.sg/nus/images/data/raffles_bulletin_of_zoology/vol65/65rbz455-465.pdf