Wednesday 23 March 2016

Stemmatopsis nangphaiensis & Stemmatopsis vanhoensis: Two new species of terrestrial Snails from Vietnam.

Terrestrial Snails of the family Streptaxidae are widely distributed in South America, Africa and Asia. In Southeast Asia 130 species have been described with 42 of them being listed as present in Vietnam. However most of the taxonomic work on the group in Vietnam was carried out between 1852 and 1915, when many modern taxonomic methods were unavailable.

In a paper published in the journal Ruthenica on 12 May 2015, Do Duc Sang of the Department of Zoology at Tay Bac University and Do Van Nhoung of the Faculty of Biology at the Hanoi National University of Education review the Streptaxid Snails of Son La Province in northwest Vietnam, and describe two new species in the genus Stemmatopsis.

The first new species described is named Stemmatopsis nangphaiensis, meaning 'from Nang Phai' in reference to the closest village to the site where the Snails were found. The Snails have small, oblique shells with six whorls at maturity. The earlier whorls are regularly spiralled, but the final whorl is strongly deflected to the right. The shells are creamy white in colour, and slightly transluscent. The species was found at a single location about 800 m above sea-level on limestone karst in Muong La District of Son La Province.

Stemmatopsis nangphaiensis. Do & Do (2015).

The second new species described is named Stemmatopsis vanhoensis, meaning 'from Van Ho' in reference to the area where it was found. These Snails have depressed helical shells with 6½ whorls at maturity. The initial whorls are regulalry coiled, with the final whorl being deflected to the right. The shells are creamy white and transluscent, with a glossy surface. The species was found at a single location about 1100 m above sea-level on limesone karst on the Moc Chau Plateau in the Van Ho District of Son La Province.

Stemmatopsis vanhoensis. Do & Do (2015).

See also... new species of Diapherid Snail from Son La Province in northwestern Vietnam.   Diapherid Snails are small terrestrial Snails found in India, China, Japan, South Korea, Thailand, Malaysia, Indonesia, Myanmar, Philippines, and Vietnam. There are about 100 species, which can be cylindrical, ovoid or hire spired, and are split into two genera, Diaphera, in which the final whorl is partially detached, and Sinoennea in which it is fully attached. lamphunensis: A new species of Cyclophorid Land Snail from Thailand. Cyclophorid Land Snails are the most abundant group of terrestrial operculate Gastropods (Land Snails having an operculum, a lid which can be used to plug the shell opening) in Africa, Asia and Australia, and comprise... new species of Cyclophoroid Land Snails from Thailand and Peninsula Malaysia.                                                                     The Cyclophoroidea are a large and diverse group of terrestrial Gastropods, occupying a range of ecological niches from species that live entirely below the soil surface to species that spend their entire life...

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