抄録
Twenty-one sexually paired hair crabs, Erimacrus isenbeckii (Brandt) were collected from the northwestern North Pacific, off Kushiro during August 1986 〜 July 1991. The paired hair crabs acted the precopulatory guarding behavior. Size distributions were unimodal for each ,sex but with few overlap in their carapace length (CL). The mean CL of male and female were 89.4 mm and 56.2 mm respectively. Other than the fact that males were invariably larger than females, there was no correlation between size of the male and size of the female with which it was paired. Sizes distribution of females paired with small (CL< 90 mm) and large (CL≧90 mm) size males were the same. Based on these data, we discussed size assortative mating and sexual dimorphism on the hair crab. In this species, male size is not correlated with female size in sexual pairs. However, cleary sexual dimorphism is observed.
