is characterized by the release of both sperm and eggs into an external
environment; sperm will fertilize the egg outside of the organism, as
seen in spawning.
Internal fertilization is characterized by sperm fertilizing the
egg within the female; the three methods include: oviparity (egg laid
outside female body) , ovoviparity (egg held within female), and viviparity (development within female followed by live birth).
Internal fertilization protects the fertilized egg or embryo from
predation and harsh environments, which results in higher survival rates
than can occur with external fertilization.
Ovoviparity is characterized by an organism retaining a fertilized
egg inside the body where development occurs and nourishment is
received from the yolk.
Viparity is characterized by an organism which has its young
develop within the female and nourishment is received directly from the
mother via a placenta.