What does viviparity mean?
Viviparity is the biological term for reproduction in which embryos develop inside the parent and the young are born alive rather than emerging from eggs. It is best known as the reproductive method of placental mammals, whose developing offspring receive oxygen and nutrients directly from the mother through the placenta. The term also has a broader, less precise meaning: the production of live young. In strict zoological classification, however, viviparity is distinguished from ovoviviparity, in which embryos remain inside the parent but are supported by stored yolk. The word is specialized and formal, appearing chiefly in zoology, evolutionary biology, embryology, and discussions of reproductive strategies. Its historical connection to Latin roots meaning “alive” and “bring forth” reflects the defining feature it names: offspring that enter the world alive.
nounA reproductive mode in which embryos develop within the parent’s body and the young are born alive rather than being laid as eggs. In its strict zoological sense, the developing embryo receives nutrients directly from the parent, as in placental mammals.
- The reproductive mode in which embryos develop within the parent’s body and live young are born; in strict zoological usage, the embryo is directly nourished by the parent.
"Viviparity allows mammals to nurture developing young inside the mother’s body before birth."
"Viviparity is the defining reproductive feature of placental mammals."
"Researchers studying the evolution of viviparity in reptiles have found that it arose independently in several lineages."
Rare in ordinary usage; the word is generally treated as uncountable when referring to the reproductive mode as a whole.
"The study compared forms of viviparity across several reptile lineages."
In mammals, viviparity turns the mother’s body into a temporary nursery, supplying developing young with oxygen and nutrients before birth.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does viviparity come from?
Viviparity was formed in English from Latin viviparus, meaning “giving birth to living young,” with the noun-forming suffix -ity. The Latin adjective combines vivus, “alive,” with parere, “to bring forth” or “produce,” while the English form preserves the Latin idea of life and birth. The word belongs to the same etymological family as viviparous and vivipary, and it also underlies compounds involving ovoviviparity.
How viviparity is actually used
This is primarily a formal biological term. In broad usage it means giving birth to live young, but specialist zoological discussions distinguish it from ovoviviparity according to how the embryo is nourished.
Easily confused with viviparity
In ovoviviparity, embryos are retained inside the parent and young are born alive, but they are nourished by an egg yolk rather than receiving nutrients directly from the parent.
Viviparity is the noun naming the reproductive condition, while vivipary is the corresponding adjective, as in “vivipary plants.”