Anaerobic wintering of crucian carp (Carassius carassius L.)-I. Annual dynamics of glycogen reserves in nature

Abstract

Abstract 1. 1. Seasonal variation in liver size (2–15% of total weight) as well as in liver and muscle glycogen content (2%–35% and 0.5–4%, respectively) of crucian carp were shown to be prominent in natural ponds with winter anoxia. 2. 2. The histological structure of liver followed the glycogen dynamics. In spring part of the liver resembled haemopoetic tissue with structures like thyroid follicles enclosed. 3. 3. The activity peak of liver lipase-esterases suggests active lipid metabolism in mid-summer only. 4. 4. The activities of glycogen phosphorylase and glucose-6-phosphatase varied not only seasonally but between years, too. 5. 5. The activity of glycogen phosphorylase in red and heart muscle was 2–3 times that in white muscle.