Daily growth banding in the shell of the cockle, Cardium edule.

Abstract

THE current interest in periodicity structures in fossil invertebrate skeletons has been related primarily to the geophysical information they provide1–3. As Neville has pointed out, however4, experimental work on recent forms has been minimal. This report describes the shell periodicity structures shown by the common British cockle Cardium edule from the Burry Inlet, South Wales. Analysis of the daily increment periodicity in these cockles, grown during 1963–1966, shows that the effects of many changes in the physical environment can be recognized in the shells and that these can be correlated with the tidal and weather records for the South Wales area. This work gives experimental support for many of the conclusions of Barker5.