Oogamy
![Oogamy in animals: small, motile sperm on the surface of an ovum](/Images/godic/202501/31/Sperm-egg3730.jpg")
Oogamy is the familiar form of sexual reproduction. It is a form of anisogamy (heterogamy) in which the female gamete (e.g. egg cell) is significantly larger than the male gamete and is non-motile. The male gametes are typically highly motile spermatozoa competing for the fertilization of the immotile egg.