Viviparous organisms are those that give birth to live young. The young develop within the mother's body.
Examples of marine life that are viviparous include:
- Marine mammals such as whales and dolphins, pinnipeds, sirenians and sea otters
- Some sharks, including blue sharks, white sharks hammerhead sharks and bull sharks, and
- Some other fish species, (e.g., the Pacific ocean perch).
The opposite (antonym) of viviparous is oviparous, in which the organism lays eggs. A type of development in between viviparity and oviparity is ovoviviparity - these animals are said to be ovoviviparous. In this case, the mother produces eggs, but they develop within her body instead of hatching outside the body.