Age-related differential catabolism in the snail Bithynia graeca (Westerlund, 1879) and its significance in the bioenergetics of sexual dimorphism

Catabolic partitioning of carbon and nitrogen was investigated to clarify the sexual dimorphism of bioenergetics in Bithynia graeca. Experiments involved post-breeding male and female snails 1, 3, and 11 months old, grazing on Aufwuchs (epiphytic scum flora). Per-snail ingestion and partitioning rates were maximal for 11-month-old snails and declined with age in both sexes. Three-month-old males had lower weight-specific rates and efficiencies than females. Eleven-month-old females had lower weight-specific rates and efficiencies than males. The youngest snails had higher rates in the various components of the energy budget than the older snails.