ABSTRACT
The systematic status of geographical variants of Arcuphantes hibanus Saito, 1992 belonging to the A. longiscapus species group, indigenous to western Honshu and Shikoku, Japan, was evaluated using morphological and molecular data. Two species, A. enmusubi Ihara, Nakano and Tomikawa, sp. nov. and A. occidentalis Ihara, Nakano and Tomikawa, sp. nov., are described, and A. hibanus is redescribed with redefinition of its taxonomic status. These three species are diagnosed by the characteristics of paracymbium, pseudolamella, and epigynal basal part. Phylogenetic trees obtained with mitochondrial cytochrome c oxidase subunit I and 16S rRNA markers showed that the variants are mutually genetically highly diverged. However, the mtDNA phylogenies failed to recover the monophyly of A. hibanus redefined herein. Contrary to the mtDNA phylogenetic analyses, a neighbor-network analysis of nuclear internal transcribed spacer 1 sequences of A. hibanus, A. enmusubi and A. occidentalis spiders showed that each of them forms a cluster. The results of mitochondrial and nuclear DNA analyses in each of the three species are briefly discussed, along with their taxonomic identities.
