Histopathological findings in a mass mortality event in a Helix aspersa maxima farm: possible association with calcium metabolism alterations

Heliciculture is becoming an interesting sustainable opportunity to increase farming yields, however effective good farming practices are lacking. Following a mass mortality event in a snail farm, samples of Helix aspersa maxima were analyzed with anatomo-histopathological techniques. Macroscopic examination revealed alterations of the gastro-enteric apparatus and of the digestive gland, which at the microscopic examination showed dysregulation in the assembly of calcium. Also, the salivary glands and the albumen gland presented different degrees of alterations ranging from atrophy to dystrophy. Interestingly, alterations of calcium localization and mineralization were observed in different organs. Our histopathological results suggest the possible implication of calcium metabolism dysregulation in contributing to the mortality events here described. Incorrect feeding and management practices, heavy metal intoxication/detoxification mechanisms, and chronic heat stress should all be considered as possible causes and further investigations focused on the pathological effects of management and environmental triggers in snail productions should be carried out to fill the gaps of knowledge in this field.