COMPARATIVE PTA STAINING OF MOLLUSCAN SPERMATOZOA

The acrosome of spermatozoa from eleven species of Mollusca (Archaeoga stropoda, Caenogastropoda and Bivalvia) was studied by transmission el ectron microscopy with the application of phosphotungstic acid-chromic acid staining on grid. Different patterns of staining were observed, which seem specific for each species and show to be important distinct ive elements within and between related taxonomic divisions. The relev ance of this cytochemical method for use in the study of phylogenetic and taxonomic relationships is discussed.