Biogeographical characteristics of coelotine spiders in Kyushu, Japan

Abstract

In this paper, the species of the subfamily Coelotinae (Araneae: Agelenidae) known to be from Kyushu, Japan are reviewed, and their biogeographical data, including those of three new genera established by Okumura (2020), are added to the article published in the last volume of this journal (Okumura, 2020, pp. 77-94). The remarkable variation of genital organs and the unique distribution of several species are specifically explained. The speciation, or morphological variation, of coelotine spiders in Kyushu is probably due to the frequent volcanic activity and rising and falling of the sea level that has occurred in the past, which may have caused the division of their habitats. Although classification problems still remain in the species group of Coelotes yaginumai, subdivided into 10 species, Coelotes ikiensis and Coelotes hataensis, which are both distributed in Kyushu, are considered to be different species by showing parapatric distributions and clear differences in the morphological characteristics of genital organs. The relationship between the shape variations of the epigyne and the homology of the form of male palp in Aeolocoelotes unicatus, Aeolocoelotes unzenensis and Tegecoelotes ignotus, is also discussed.