Seasonal variations in chemical composition of the female gonad and storage organs in Pecten maximus (L.) suggesting that somatic and reproductive growth are separated in time

Glycogen, protein, and lipid composition were determined in the female part of the gonad, striated adductor muscle, and digestive gland during 1 year in great scallops (Pecten maximus). The scallops were sampled from Raunefjorden outside Bergen on the west coast of Norway. From the spring phytoplankton bloom in March to June, gonad growth, spawnings, and rebuilding took place; whereas, no somatic growth was seen during this period. A marked increase in digestive gland protein during the spring bloom may have represented an increase in digestive capacity induced by the increased food levels. Between June and August, a concentrated period of somatic growth and increased storage was seen; whereas, the Female gonads showed no signs of rebuilding, because they decreased due to spawning activity. Gonad rebuilding tool; place between October and December. Reproduction in many populations of P. maximus is regarded as more or less continuous, since individuals with filled gonads can be found all year. However, for the population in this study, it seemed that no energy was allocated to the gonads in the period starting in June, with somatic growth and storage, until the gonad rebuilding in October, even though the gonads were still containing presumably growing oocytes. From these results, we suggest that switches in energy allocation divide the season in two pans in these scallops: (1) priority of reproductive growth from October to June: and (2) priority of somatic growth and storage from June to October.