Studies on the survival time of the eupyrene and oligopyrene spermatozoa of the prosobranch,Vivipara bengalensis (Lamarck)

Summary Vivipara bengalensis, like many other gastropods, produces two types of spermatozoa viz., eupyrene (normal) and oligopyrene (abnormal). The eupyrene ones are comparatively small and uniflagellated, whereas the oligopyrene ones are much larger, worm-like and each with a tuft of tail flagella. Eupyrene and oligopyrene spermatozoa reveal in vitro differential survival characteristics; the eupyrene spermatozoa exhibit considerably shorter survival as compared with their oligopyrene counterparts.