Body distribution and seasonal changes in the glycogen content of the common sea mussel Mytilus edulis

Abstract

1. Glycogen content was measured in the sea musselMytilus edulis, and found to be present in amounts ranging from 10 to 35 per cent dry weight of the soft parts.

2. The annual glycogen cycle was followed for five different fractions: the digestive gland, muscles (including those of the foot), gills, mantle and residue. Seasonal changes in gills and muscles were much smaller than in the other tissues.

3. The annual glycogen cycle for the total animal consisted of a rapid increase in spring and early summer, followed by small fluctuations in the late summer. In autumn and early winter there was a gradual decline reaching a minimum of about 10 per cent in February and March.

4. There was an interrelation between seasonal changes in dry weight and the percentage of glycogen.