Observations on activity pattern and resting site fidelity in the pulmonate limpet Siphonaria lessoni

LÓPEZ GAPPA, J.; TABLADO, A.; MAGALDI, N.H.

THALASSAS (SANTIAGO DE COMPOSTELA)

Universidade de Vigo

Lugar: Santiago de Compostela; Año: 1996 vol. 12 p. 27 - 36

0212-5919

Siphonaria lessoni (Blainville) was studied at Quequén, Argentina (38º35’S, 58º42’W). Two groups of 20 limpets located at different sites were observed on rocky intertidal platforms at Carballido, and another group was studied within Quequén Harbour. Activity was recorded hourly for 24 h periods. Foraging movements of S. lessoni in Carballido occurred exclusively during ebbing tides, both by day and night. Activity began when the limpets were exposed and ended when the surface dried, and was longer at night than during daytime due to a more extended humidity period. No activity was recorded for 24 h in 45% of the limpets. S. lessoni shows one or two daily foraging periods, depending on the number of times that a particular site is reached by the tide. Activity was almost absent during the midday ebbing tide in limpets at Quequén Harbour, due to a rapid desiccation of the substratum. Homing behaviour was absent in Carballido. Resting sites were found to be displaced for a few centimetres after short periods. After 2-3 months, some limpets were located up to 2.8 m upshore. Spawning occurred during submersion. The importance of desiccation stress and dislodgement by wave action as factors determining the activity pattern of S. lessoni is discussed.