Carbohydrate oriented metabolism of Planorbis corneus (mollusca, planorbidae) during starvation

Abstract

1. 1. Of the pre-starved dry weight of soft parts of P. corneus, polysaccharides, proteins, and lipids made up 34.9, 29.9, and 12.9 per cent respectively. 2. 2. These constituents were used most rapidly during the first few days of starvation. After 58 days of starvation, 56 per cent of the snails were dead. At this time, 95 per cent of the original polysaccharides were metabolized; 49 per cent of the proteins; and 22 per cent of the lipids. The loss of these three constituents accounted for 81 per cent of a total dry weight loss of 62.3 per cent. 3. 3. Death appeared due to a depletion of carbohydrate reserves, since there were still substantial amounts of lipids and proteins remaining through 58 days. 4. 4. It was concluded that the metabolism of P. corneus was carbohydrate-oriented.