The glands of the larval foot in Pecten maximus L. and possible homologues in other bivalves

Abstract

A survey by Yonge (1962) of the byssal apparatus in the Bivalvia indicates that the formation of byssus is a larval characteristic which may or may not be retained in the adult. Some species such as the mussel, Mytilus edulis, retain the byssal attachment but have the ability to break the byssus and move over a limited area. Others, such as the scallop, Pecten maximus, lose the byssus entirely, become unattached and move by swimming. Yet others, such as the oyster, Ostrea edulis, relinquish all mobility at metamorphosis by cementing the shell to the substratum, and after metamorphosis lose all trace of the foot. Ostrea, Mytilus and Pecten therefore encompass a wide variety of life styles in the adult and are chosen as examples for detailed comparison of the byssus forming glands and other foot glands in the pediveligers.