the proportions of oocytes penetrated ( i.e . enlarged sperm head or male pronucleus and corresponding sperm tail ) were 0 , 10.0 and 16.7 % with ejaculated spermatozoa , and 3.3 , 19.6 and 26.4 % with epididymal spermatozoa preincubated in modified krb , oviduct and uterus , respectively .
C0037844
sperm head
C0037868
spermatozoa