A new species of the genus Arrup from a limestone cave in Akiyoshi-dai, Western Japan (Chilopoda, Geophilomorpha, Mecistocephalidae)

Abstract

Arrup akiyoshiensis Tsukamoto & Shimano, sp. n. is described from a limestone cave, Kagekiyo-ana, in Akiyoshi-dai, one of the largest karst regions in Japan, Yamaguchi prefecture. It is distinguishable from 14 valid named congeners by some unique characteristics including entire areolation on the cephalic pleurite, elongation of distal part of female gonopod, and a tubercle on forcipular segment II. In addition, the 18S rRNA gene sequences of A. akiyoshiensis Tsukamoto & Shimano, sp. n. and A. ishiianus, one of the most morphologically similar species, differed by four bp out of 1821 bp. The fact that only troglobionts and troglophilic species are found in the collection site suggests that this new species might be a cave-dweller.