Variations in food intake of Pecten maximus (L.) from the Bay of Brest (France): Influence of environmental factors and phytoplankton species composition

Previous studies carried out in the bay of Brest on daily shell growth of P ecten maximus have demonstrated that temperature is a major control on dail y shell growth in contrast to food supply. However, repeated events of slow growth have been observed during diatom and dinoflagellate blooms. The aim of this study was to determine how fluctuations in environmental parameter s influence P maximus food intake and daily shell growth rate. In 1995, P m aximus food intake and growth were highest when Cerataulina pelagica (diato m) blooms occurred and lowest during Gymnodinium cf. nagasakiense (dinoflag ellate) blooms. During blooms of other diatom species, P maximus food intak e and growth were high when the algal concentration did not exceed a critic al threshold, dependent upon the dominant species and sedimentation rate of diatoms. These results demonstrate that the morphological and physiologica l features of phytoplankton bloom species strongly affect benthic microphyt ophagy, a component of benthic-pelagic coupling. (C) 2001 Academie des Scie nces/Editions scientifiques et medicales Elsevier SAS.