Ovoviviparous

Ovoviviparous is the reproductive technique of many animals.

It means giving birth to a well developed offspring that has been developed from an egg that has hatched within the mother before giving birth or just after being extruded from the mother. The hatched young receives no metabolic input from the mother, but is in a protected environment.

This is used by some fishes, including several sharks, and reptiles, and many invertebrates.