Fig. 3.
Scanning electron micrographs of Octopus vulgaris spermatozoon collected from (A) the spermatophore, with an intact outer membrane covering the acrosome, and (B) from the female oviducal gland, following post-ejaculatory modifications to sperm (PEMS) to reveal the corkscrew-shaped acrosome. Inset in A shows magnification of the acrosomal region. Arrows indicate indentations separating the acrosome, nuclear and midpiece regions. Adopted with permission from Tosti et al. (2001). Scale bars: A, 3.0 μm; B, 2.0 μm.