Fine structure and acid phosphatase localization of hemocytes in the freshwater snail Viviparus ater (Gastropoda, Prosobranchia)

The ultrastructure of hemocytes of the freshwater snail Viviparus ater was studied. A single cell type characterized by the presence of thin pseudopods, polymorphic nucleus, and α-glycogen granules was found. Moreover, cytoplasmic granules with different morphologies were observed, suggesting different stages of granule maturation. These granules show variable amounts of acid phosphatase reaction products. Due to its morphological and functional characteristics, this cell type belongs to the spreading hemocytes described in other gastropod molluscs, confirming light microscopy observations. © 1990.