The Oniscus asellus complex (Crustacea: Isopoda: Oniscidea) in the Iberian Peninsula with the description of a new species

Abstract

Extensive fieldwork in the northwest of the Iberian peninsula has resulted in the discovery of Oniscus galicianus sp. nov. which is closely related to ancarensis Bilton, and asellus Linnaeus. Together these three taxa are considered to form a distinct clade within the genus-the asellus complex. O. galicianus is described and distinguished from other members of the complex using pleopodal anatomy and multivariate morphometry. The discovery of galicianus significantly modifies previous ideas concerning the distribution and evolution of the asellus complex in southwest Europe. Only the nominate subspecies of O. asellus occurs in the Iberian peninsula. This finding is discussed and the suggestion made that the intraspecific taxa of asellus differentiated elsewhere in western Europe.