Species diversity and geographic differentiations of reproductive organs and body size in the genus Cybaeus (Araneae: Cybaeidae) in Japan

Abstract

The spider genus Cybaeus (Cybaeidae) shows enormous diversity in both reproductive organs and body size in Japan. The number of described species of Japanese Cybaeus has reached 70 species and there still remains many undescribed species. Most of the species also show extraordinary geographic differentiations mainly in their reproductive organs. This review article briefly summarizes present knowledge on their modes and patterns of geographic differentiation, copulatory organs, circular overlap, species assembly, and biogeography.