Highly conserved karyotypes of Systenocentrus japonicus and Paraumbogrella pumilio (Opiliones: Sclerosomatidae: Gagrellinae) supporting their close relationship

Abstract

Karyotypes of two sclerosomatid harvestmen, Systenocentrus japonicus and Paraumbogrella pumilio, were analyzed. Males of the both species shared a very similar karyotype with 2n＝10 comprised of four metacentric pairs of autosomes and a submetacentric X and a metacentric Y chromosome. The karyotype was conservative also within each species. Sharing of the conserved karyotype supports close relationship of the two species, which is also suggested by several other morphological and ecological characteristics. Distribution maps of the two species are provided.