Ultrastructural analysis of mature spermatozoa of Hyalinoecia tubicola (OF Müller)(Annelida Polychaeta)

摘要: The Hyalinoecia tubicola (O. F. Müller) spermatozoon shows an organization recalling that which is characteristic of the primitive type of sperm as described by FRANZÉN (1970). The head is conical in shape, with an elongated acrosomal complex; the middle piece contains five spherical mitochondria, encircling a collar formation, with an elaborate anchorage vesicle, delimited by a membrane surrounding an inner digiti-form space, which is dilated in its apical portion and filled with a poorly electron-dense granular material; the acrosomal tube is missing.