1988 年 7 巻 1-2 号 p. 41-47
The infestation of barnacles with Polydora spp. is discussed in relation with the size and structure of the host. The frequency of barnacles attacked by Polydora was relatively low in small sizes (up to 10mm in diameter), increasing to a high rate in the largest sizes during May to July. Barnacles infected with Polydora decreased in number markedly through late fall and no parasitism was observed in the winter. Polydora seems to attack specific regions of the shell plates for all the data combined. It is considered that barnacles infected with the pest die during August and September.