The effect of food supply on metamorphosis and post-larval development in hatchery-reared Pecten maximus

Variations in growth and survival of hatchery-reared post-metamorphic juveniles of Pecten maximus prompted experiments on settlement and post-larval development. The effects of food supply on P. maximus metamorphosis and post-larvae were studied over 4 and 8 week periods. In all experiments, and regardless of the environmental conditions, P. maximus metamorphosed over a 2-3 week period with values of 30% to 50%. After this period, spat numbers increased slightly. Spat mortality was generally low, with values reaching only 10% to 30% after a month of rearing. Mortality increased throughout the second month, however, and reached 50% at the end of some trials. Poor growth was noted when post-larvae were starved for 2 months (10 mum day(-1)), whereas food levels ranging from 7 to 66 cells mul(-1) had a weak influence on post-larval development during the first month (69 to 75 mum day(-1)) suggesting food requirements of 6000 cells post-larvae(-1). (C) 2001 Elsevier Science B.V. All rights reserved.