Maturation of mosquito spermatozoa during their transit throughout the male and female reproductive systems

The testes, seminal vesicles and spermathecae of 22 species of mosquitoes belonging to the genera Aedes, Anopheles, Culex, Mansonia and Toxorhynchites are investigated under the electron microscope. Modifications of the acrosome and sperm wall occur during the transit of the spermatozoon from the lower region of the testes to the spermathecae throughout the seminal vesicles. The origin and fate of the cell coat and the possible roles of somatic cell layers both in the testes and the seminal vesicles are discussed.