Observations on the Morphology of the Mantle Folds of the Pediveliger ofOstrea EdulisL. and their Function During Settlement

Abstract

Stafford (1913) rejected the view of many early workers (see Ryder, 1883, 1884; Huxley, 1883; Horst, 1886) that oyster larvae cemented themselves to the substratum with secretions of the mantle edge. He thought that the mantle margin could not be extended sufficiently to form the extensive area of cement that he found on the left valve of cemented larvae. Furthermore, he argued that the mantle could not secrete so much material in the short period that larvae took to cement. He deduced from the much reduced state of the ‘byssus gland’ in settled larvae that this gland was the source of the cement and suggested that the cement was spread over the shell by the foot. Nelson (1924), Prytherch (1934), Cole & Knight-Jones (1939) and Cranfield (19736, c) have clarified the role of the foot in cementing. Nelson (1924) also noted that cementing oyster larvae extended the mantle margin over the substratum but considered that this action spread the cement discharged by the foot and that the folds themselves did not secrete more material. The other authors, like Stafford, have dismissed or ignored any part the mantle folds might play in cementing.