Settlement of the gastropod Concholepas concholepas on shells of conspecific adults

Abstract

Competent larvae of the commercially important marine gastropod Concholepas concholepas (Gastropoda: Muricidae) ‘loco’, were collected in the field and exposed in the laboratory to adult conspecific shells with and without barnacle epibionts. Settlement and metamorphosis was induced by the presence of barnacles on shells of live or dead conspecifics, but not by C. concholepas shells without barnacles. Results from laboratory experiments agreed well with field surveys showing the presence of recruits on conspecific shells overgrown with barnacles in shallow subtidal habitats (∼3–30 m deep), suggesting the potential importance of barnacles in inducing settlement and metamorphosis of locos under natural conditions. Most loco recruits were found below the C. concholepas shell apex, feeding on barnacles, inhabiting crevices among them, and inside dead barnacles. The mean size of recruits on locos' shells increased over four months from the beginning of the settlement season and no individual larger than 1·5 cm was observed, suggesting that they abandon adult loco shells at this size, roughly 5–6 months after settlement.