RESUMO
Microcystin (MC) concentrations were measured in the alimentary tract, digestive gland, and remaining visceral mass of adult pulmonate snails (Lymnaea stagnalis) exposed to cyanobacteria known to contain MC. The highest proportion of total body MC content was measured within the alimentary tract (83%), though an appreciable proportion (17%) was also found within the digestive gland tissue. This provides conclusive evidence for the limited digestion of toxic cyanobacteria and subsequent uptake and accumulation of MC by the digestive gland of L. stagnalis. Additionally, pure microcystin-LR was orally administered to adult L. stagnalis to investigate the potential for toxic effects. Exposure to microcystin-LR induced histopathological alterations of the digestive glands consistent with those reported elsewhere for mammals and fish, indicating a common mode of toxicity to both vertebrates and invertebrates.
