[Ultrastructure of the spermatozoids of the pulmonate molluscs, Trichia hispida and succinea putris].

The ultrastructural study of spermatozoa of hermaphroditic land molluscs Trichia hispida and Succinea putris has shown that the general pattern of their structure is similar. At the same time differences were found in the fine structure of acrosome, centriolar region (neck) and mitochondrial derivate (accessory nucleus). The mitochondrial derivate of spermatozoa of both the species contains three secondary spirals of varying length (vs. one-two in other species of pulmonate molluscs).