CARBOHYDRATE-METABOLISM DURING OSMOREGULATION IN CHASMAGNATHUS-GRANULATA DANA, 1851 (CRUSTACEA, DECAPODA)

1. Since glucose is one of the main energetic substrates for general m etabolic processes in crustaceans, analysis of carbohydrate levels can furnish information on the energy metabolism of intact animals during osmoregulation. 2. Different groups of Chasmagnathus granulata were t ransferred to different salinities (0 and 40 parts per thousand), and the glucose and glycogen concentrations in blood, gills, muscle and he patopancreas were determined at the beginning of the experiment and 24 , 72, 168 and 360 hr after the salinity changes. 3. Differences in tis sues carbohydrate levels were observed between summer and winter, that reflected differences in reserve mobilization. 4. In the summer, hypo - and hyperosmotic shocks induced an increase in carbohydrate levels i n almost all tissues studied, indicating gluconeogenesis. 5. In the wi nter, a carbohydrate mobilization occurred only in the gills and hepat opancreas after both osmotic shocks. 6. Thus, the substrate reserve us ed for energy production required for,osmoregulation seems to be depen dent on the season and tissues.