Substrate variety and host preference of the epizoic limpet Lottia tenuisculpta (Patellogastropoda: Lottiidae)

ABSTRACT Substrate variety and host preference of the epizoic limpet Lottia tenuisculpta were investigated based on specimen and field observations. Specimen observation revealed the presence of the limpet on 33 species of Mollusca and two species of Crustacea, and it predominantly used Tegulidae and Muricidae throughout its geographic range. Some of the substrate molluscs had radula traces and home scars probably engraved by L. tenuisculpta. Field observations conducted on the rocky shore of Shirahama, Wakayama, Japan, revealed the presence of L. tenuisculpta on 12 species of molluscs. The tegulid Omphalius nigerrimus and the muricid Reishia clavigera were its major substrates in the locality. The results of both sets of observations suggest that L. tenuisculpta is a host-general facultative epizoite and its host preference is family-specific. The choice of host species by L. tenuisculpta might be determined by the abundance and morphological and biological restrictions of the preferred substrates in each locality. The host-general and facultative nature of the limpet allows it to show geographical host conversion and contribute to favouring epizoic behaviour. Home scars of L. tenuisculpta on the hosts suggest that the limpet inhabits the same individual of the substrate species for an extended period.