Figure 1: Different head and acrosome images of sperm. (A) The four numeric parameters of head shape. SD, standard deviation; AP, anteroposterior. (B) Schematic images of different acrosomes: (a) Normal acrosome, (b) small acrosome, (c) large acrosome, (d) skew acrosome, (e) amorphous acrosome, and (f) without acrosome. (C) Distribution of different acrosome morphologies amongst spermatozoa with different head shapes in comparison to normal head shape. P*<0.05,**<0.01,***<0.001.