抄録
Population dynamics on Capitella capitata has been studied in Amakusa since November 1979. Though the population reproduced almost throughout the year, the seasonal fluctuations of population size were very large. Size cohorts were detected in the size distribution, because spawning occurred synchronously. Their life cycles were traced by the close quantitative investigations. The prereproductive period was for 4 to $ weeks and b cohorts occurred only for 4 months. The survivorship curve was estimated by the new technique, using computer simulation.
