[In vitro development of hemolymph granulocytes of Biomphalaria glabrata (Gastropoda, Planorbidae). Study by scanning electron microscopy].

The morphological evolution in vitro of Biomphalaria glabrata granulocytes on a cover-glass is described by scanning electron microscopy. 4 stages have been characterized: stage 1: globular cells showing low adhesion to cover-glass; stage 2: flattened cells in contact with substrate over a large surface, which present two well differentiated cytoplasmic zones: an endoplasm in which the nucleus is embedded and an ectoplasm which extends into very thin filopodia with a spherical terminal bulb; stage 3: cells which are very flattened and which adhere to each other; stage 4: cells which are completely spread on the cover-glass, in which the ectoplasm includes the filopodia. These 4 stages probably represent the granulocyte ontogenetic stages in their role in cellular defense against foreign substances.