ムラサキウニの生殖年周期と産卵月齢周期性 The Annual Reproductive Cycle and Lunar Spawning Rhythms of the Purple Sea Urchin Anthocidaris crassispina
The annual reproductive cycle and lunar spawning rhythms in the spawning season of the purple sea urchin <i>A. crassispina</i>, which lives in Mera Bay of South Izu in Shizuoka, were examined by the successive change of the gonad index and histological observation of the gonad. The following is the annual reproductive cycle of the purple sea urchin; the gonad become to develop from January to May, the spawning season to be from June to August, and the gonadal growing action to degenerate from September to December. Moreover, it was suggested that this cycle is closely related to the annual change of the sea water temperature. As the population of this species spawned several times every full moon period in the spawning season, they were thought to have lunar spawning rhythm that spawns once each the lunar period. It was suggested that the gonad in the spawning season could recover for the next spawning in about a week.
日本水産学会誌 63(1), 17-22, 1997-01-15