Distribution of the bonnet limpet, Hipponix conicus (Gastropoda : Hipponicidae), among host species in western Kyushu, Japan

The bonnet limpet, Hipponix conicus (Schumacher, 1817), adheres to the shel l surface; of other snail species. In order to discuss the ecological relat ionships between fi. conicus and many host snails, the distribution of this limpet among its potential hosts was determined in western Kyushu, Japan. A total of 26 snail species was collected, and H. conicus was found on 13 o f them. The mean adhesion frequencies and mean numbers of H. conicus per sn ail were significantly different among the host species. Among eight host s pecies, more H. conicus were found an shells with living snails than on she lls with hermit crabs. The number of H. conicus per host and shell length o f H. conicus tended to increase with host size for 11 and eight host specie s, respectively. Host snail individuals with at least one H, conicus tended to be larger than those without any H. conicus for ten Species. Overall, o ur data indicate that the quality of shells as a host differs among host sp ecies (living Snails and hermit crabs) or host sizes. The difference in H. conicus loads could be caused primarily by preferential adhesion to differe nt hosts and/or differential growth and/or survival on different hosts.