Union of an egg cell with a sperm during sexual reproduction inside the body of a parent; occurrence of internal insemination as the mode of combining sperm and egg.
And internalfertilization can be a bit difficult if you don't have limbs to help you grasp your partner.
2
Like sharks the skeletons of chimaeras are composed of cartilage, and the males have claspers for internalfertilization of females.
3
The seminal plasma of some species with internalfertilization contains anti-aphrodisiac molecules that deter promiscuity in post-copulatory females, conferring fitness benefits to the ejaculating male.