Fig. 4

Diagram of spermatozoa of Adelomelon ancilla. a Internal view of eusperm. TEM. Note the constriction of subacrosomal invagination and the U-shape of electron-dense mitochondrial elements in the midpiece. b External and general view of parasperm. Light microscopy. Trasversal sections observed by TEM. Note the TS of the apical, medial, and final region. A acrosomal complex, ab apical bleb, ar axial rod material, av acrosomal vesicle, am accessory membrane, an annulus, ax axoneme, bp basal plate, ct acrosomal vesicle constriction, dv dense vesicles, ep endpiece, g putative granules, gp glycogen piece, m mitochondria, mp midpiece, N nucleus, U U-shaped defining edge of mitochondrial element. Not drawn exactly to scale