Synonymy and Generic Reassignment of the Japanese Earthworm Metaphire acincta comb. nov. (Annelida: Oligochaeta: Megascolecidae)

Abstract

The morphologies of two nominal species of earthworm, Amynthas acinctus (Goto and Hatai, 1898) and Metaphire yezoensis (Kobayashi, 1938), were studied and compared. We found copulatory pouches behind the male pores of A. acinctus and thus conclude that this species should be transferred to the genus Metaphire. The intraspecific variability of specimens from Nagano Prefecture in central Japan, which closely agree with the original description of M. yezoensis, has been assessed. Our observation strongly suggests that M. yezoensis and Metaphire acincta comb. nov. are conspecific, and thus the latter is considered to be a senior synonym of the former.