Intra-and interspecific interactions among several gastropods with special reference to kleptoparasitis

在和歌山白滨的岩石潮间带海岸上，有五种致命的物种栖息在以变型贝（Hormomya mutabilis）为主的浅潮池中。利用实验室和野外的延时录像对海螺的行为进行了分析，以了解海螺种内和种间相互作用的方面。桑葚和fusca Muricodrupa通过在贻贝壳上钻一个洞来攻击变异嗜血杆菌。musiva有时会剥去同种个体的猎物。泰国clavigera Form C通过将其喙插入猎物的瓣膜之间来攻击贻贝，并清除贻贝剩余的肉或使捕食者失去贻贝。缩月牙藻和玛氏月牙藻很少攻击贻贝，而是依赖于其他掠食者打开的贻贝，这些掠食者包括食腐和盗寄生。有时会攻击同种或其他海螺。进行了一些实验，以了解其他物种存在的影响。与musiva一起饲养时，收缩伊蚊的生长速度更高。另一方面，构造乳杆菌的存在不影响musiva的生长。musiva似乎通过增加攻击频率来弥补偷窃寄生的损失。在以变异嗜血杆菌为主的潮池中，发现了非常复杂的种内和种间相互作用。特别是，偷窃寄生虫似乎在那里扮演着重要的角色。为了了解这个独特的海螺群落，需要进一步的实验和观察。

Five muricid species inhabit shallow tidepools dominated by the mussel Hormomya mutabilis in the rocky intertidal shore of Shirahama, Wakayama. Their behaviors were analyzed using a time-lapse video recorder in the laboratory and field to know the aspect of intra- and interspecific interactions among whelks. Morula musiva and Muricodrupa fusca attacked H.mutabilis by drilling a hole on a mussel shell. M.musiva sometimes robed a conspecific individual of a prey. Thais clavigera Form C attacked a mussel by inserting its proboscis between prey valves, and scavenged the flesh of a mussel remained or robed a predator of its mussel. Ergalatax contractus and Cronica margariticola seldom attacked a mussel, but depend on mussels opened by other predators, which includes both scavenging and kleptoparasitism. E.contractus sometimes attacked a conspecific or other whelk.Some experiments were conducted to know the effect of the existence of other species. The growth rate of E.contractus became higher when they were kept with M.musiva. On the other hand, the growth of M.musiva was not affected by the existence of E.contructus. M.musiva seemed to compensate the loss of kleptoparasitism with increasing the frequency of attacking.Very complicated intra- and interspecific interactions were seen among muricid species inhabiting the tidepools dominated by H.mutabilis. Especially, kleptoparasitism seems to play an important role there. To understand this unique whelk community further experiments and observations are needed.