ABSTRACT
An investigation was carried out on a subtidal population of Echinocardium cordatum, over a period of three years, across a bathymetric gradient, from the clean fine sands of the shallower area to the muddy sands of the bay of Douarnenez. Periods of spawning and recruitment are defined, the breeding season being in summer. Large variations in the densities of the recruited juveniles occurred from one year to another. From the length frequency histograms, plurimodal year classes were shown and the life-span of this population was determined. A growth curve is plotted showing a rapid growth process in summer and a slowing down in winter. The spatial distribution analysis revealed some heterogeneity, suggesting migration. A comparison is made with other published data from the geographical range of Echinocardium cordatum.
