Viviparous

Definition

Producing live offspring that develop from embryos nourished directly by the maternal parent, rather than from eggs laid and incubated externally. In viviparous reproduction, the embryo receives metabolic support—typically via a placenta-like structure, secretions, or maternal tissues—until birth of a free-living juvenile. Contrasts with oviparity (egg-laying) and ovoviviparity (eggs retained internally without maternal nutrient transfer beyond the yolk).

Etymology

From Latin vivus (alive) + parere (to bear).

Example

The tsetse fly Glossina morsitans is viviparous: a single larva develops inside the female's uterus, nourished by milk glands, until deposited as a mature third-instar larva ready to pupate.

Related Terms

• Oviparous
• Ovoviviparous
• larviparous
• pupiparous
• aplacental viviparity
• placental viviparity
• ovo-larviparity

Usage Notes

In entomology, strict viviparity is relatively rare; many 'live-bearing' insects are actually ovoviviparous (eggs hatch internally) or larviparous (active larvae deposited). The distinction matters for life-history classification: true viviparity requires sustained maternal provisioning beyond the yolk, whereas ovoviviparity involves retention of self-sufficient eggs. Some specialists reserve 'viviparous' for placental or pseudoplacental nourishment and use 'larviparous' for flies that deposit developed larvae.