Abstract
The distribution and reproductive biology of the hermit crab Pagurus nigrofascia Komai, 1996, were studied from March 1992 to May 1995 at Kattoshi, Hakodate Bay, northern Japan. The species was distributed in the upper intertidal zone, mainly at pebble-covered areas on the shoreline. Ovigerous females were observed from April to February. Developmental stages of incubated eggs were synchronized within the population. The appearance of ovigerous females and examination of developmental stages of eggs revealed that the main spawning month was May, females oviposited once a year, and eggs were incubated for about nine months through the hot summer and cold winter. This long incubation period is a striking reproductive characteristic compared with other Pagurus spp., and suggests a wide variety of reproductive features may exist within the same genus Pagurus, even among species living in the same habitat.
