Possible occurrence of reproductive isolation between two geographical clades of a laniatorid harvestman Pseudobiantes japonicus (Arachnida: Opiliones: Epedanidae) in Shikoku

Abstract

Phylogeographic analyses of a laniatorid harvestman Pseudobiantes japonicus Hirst, 1911 (Arachnida: Opiliones: Laniatores: Epedanidae) in Japan have provided evidence for long-term isolation among allopatric clades from different refugia, and there was a possible narrow hybrid zone between two different phylogroups, Clade A and Clade B, in central part of Shikoku. We performed PCR-RFLP analyses of mitochondrial DNA (mtDNA) and nuclear DNA (nrDNA) to clarify whether hybridization or introgression between them occur or not in the area where ranges of Clade A and Clade B meet. We were able to detect neither heterozytes for nrDNA genes nor the incongruence between mtDNA and nrDNA. These results indicated that P. japonicus have not experienced hybridization or introgression between Clade A and Clade B in the contact zone, suggesting that they could be considered as cryptic species.