Short- and long-term movements of the patellid limpet Patella flexuosa within gaps in intertidal mussel beds

Short-term and long-term movements of the patellid limpet PatellaflexuosaQuoy & Gaimard were studied on an intertidal rockyshore where a mytilid, Hormomyamutabilis (Gould), formed anextensive mussel zone. At low tide, all the limpets were foundrestingwithin gaps in the mussel zone, which were formed after massdislodgement of themussels by waves. The foraging areas ofall the marked limpets were restricted to within the gapsduringfour 24h diving observations. All of these limpets displayedhoming behaviour after shortexcursions with a maximum averagedistance of 6.7 cm from their homes. During short-termobservationperiods of about 4–5 days, no marked limpets moved fromone gap to anothergap across the mussel bed of H. mutabilis.During long-term observation periods of onemonth, however,10–30% of marked limpets shifted their homes to differentgapsthat had a lower limpet density. The shell length of theseemigrants was, in general, significantlysmaller than that ofnon-emigrants. The percentage of emigrants tended to be higherin summerand autumn than in winter and spring. The movementof P. flexuosa within patchyhabitats is discussed with a focuson the difference in site fidelity between small and largelimpets. (Received 14 April 1998; accepted 7 September 1998)