Propagation and growth of Ponnotheres pholadis living in mantle cavity of Hiatula acuta

This paper presents the study of the propagation and alternation of generations of Pinnotheres pholadis by observing yearly development and measuring carapace breadth of P.pholadis living in mantle cavity of Hiatula acuta. The reproductive period of P.pholadis was from March to October, and two breeding peaks were respectively from the last ten-day period of April to the first ten-day period of June, and from the last ten-day period of September to the first ten-day period of October. The alternation of generations of P.pholadis was as follows:Individuals hatching in spring matured next year and two breeding periods and died after the second breeding period. Their olds were one and half year. Individuals hatching in the autumn had one breeding period next year, and another breeding period in the third year, their olds were two years. P.pholadis got into mantle cavity of Hiatula acuta when the carapace of P.pholadis was 3.2 mm wide. Before that,they had been free-living.