Viviparous

Viviparous animals bear live young that have developed inside the mother's body. Most familiar to us in mammals, there are a few unexpected ocurrences in animal groups usually associated with egg-laying such as reptiles, amphibians, fish and scorpions. The term can also be applied to some plants, such as certain kinds of succulents and waterlilies, where the seeds germinate while still attached to the parent.

Watch video clips from past programmes (1 clip)

In order to see this content you need to have an up-to-date version of Flash installed and Javascript turned on.

Species with this adaptation

Mammals

About

A viviparous animal is an animal employing vivipary: the embryo develops inside the body of the mother, as opposed to outside in an egg (ovipary). The mother then gives live birth. The less developed form of vivipary is called ovoviviparity, which, for instance, occurs in most vipers. The more developed form of vivipary is called placental viviparity; placental mammals are the best example, but other animals have also adapted by incorporating this behavior, such as in scorpions, some sharks, some snakes, and in velvet worms. Certain lizards also employ this method such as the genera Tiliqua and Corucia. The placenta is attached directly to the mother in these lizards which is called viviparous matrotrophy. Viviparous offspring live independently and require an external food supply from birth. There are numerous advantages and disadvantages to being viviparous.

There is a relationship between sex-determining mechanism and whether a species bears live young or lays eggs. Temperature-dependent sex determination does not work in the sea, so marine viviparous species use genotypic sex determination (sex chromosomes).

Viviparous plants produce seeds that germinate before they detach from the parent. In many Mangroves, for instance, the seedling germinates and grows under its own energy while still attached to its parent before dropping into the water in order to transport away.

Read more at Wikipedia

This entry is from Wikipedia, the user-contributed encyclopedia. If you find the content in the 'About' section factually incorrect, defamatory or highly offensive you can edit this article at Wikipedia. For more information on our use of Wikipedia please read our FAQ.

Other Reproduction Adaptations

Explore the BBC

BBC © MMIX

The BBC is not responsible for the content of external internet sites.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.