A new species of the genus Perionyx Perrier, 1872 (Clitellata: Megascolecidae) and two new records from Eastern Himalayas, India

A new species Perionyx manebhanjangensis sp. nov. is described from Darjeeling, West Bengal, a part of the Himalayan Biodiversity Hotspot. The new species belongs to the quadrithecal group, characterized by spermathecal pores in intersegmental furrows 6/7 and 7/8. Within this group, the new species is closely related to Perionyx pallidus Stephenson and Perionyx alatus Stephenson in the presence of penial setae and last pair of hearts in segment 13.

The new species can be distinguished from P. pallidus by the extent of clitellum, prostate glands and ornamentation of the penial setae, and from P. alatus by the origin of the intestine, position of the male and spermathecal pores. Moreover, two exotic peregrine species Amynthas minimus (Horst) and Eukerria saltensis (Beddard), collected from the vicinity of Mirik Lake in Darjeeling, West Bengal are recorded for the first time from India.

This study provides detailed descriptions of the new species and new records, along with illustrations of key characters. In addition, a taxonomic key for the genus Perionyx is provided.