Figure 8. Ultrastructure: Formation of concentric layer around sperm heads undergoing engulfment. Al: autolysosome; Cd: cytoplasmic droplet of spermatozoa, L: lysosome, Mit: mitochondria, Sp: spermatozoa (H: head, Mid: midpiece, T: tail). Rectangular area showed enlarged area. Black arrow: interconnected zone, White arrow: electron translucent zone, Curved black arrow: numerous concentric layers around spermatozoa head, Thick white arrow: reduced electron translucent zone, Arrowhead: autophagic activity. Scale bar: (A, C) 5 μm and (B) 2 μm.