Annual changes in the nutritive state of North Sea dab

Abstract

The nutritive state of dab Limanda limanda was investigated over a 2-year period at a fixed sampling site northwest of Helgoland (German Bight, North Sea), with respect to feeding habits and the accumulation of biochemical storage products. Ophiuroids formed the main weight of food organisms (50%) while polychaetes (10%), molluscs and crustaceans (<5% each) were less frequent. Feeding activity in males varied between summer and winter, while females fed more constantly. The condition factor and the hepatosomatic index showed characteristic seasonal cycles in both sexes. The glycogen content in the liver reached 40-60 mg g 1 FW in summer and fell to about 10-20 mg g 1 FW in late winter. Total lipids of the liver showed a distinct seasonal cycle with 400 mg g 1 FW in summer and a minimum of 50-100 mg g 1 FW in spring. The lipid content of the muscle ranged from 5 to 6 mg g 1 FW and did not vary significantly between seasons.1996 The Fisheries Society of the British Isles