They are the ones that develop and feed inside the body of the pregnant mother until the moment of birth. Once they are born, they live autonomously, since they are fully developed. An exception to this rule are viviparous marsupials, whose offspring are born prematurely and need to perfect their training process inside the animal’s pouch, such as kangaroos.
Almost all mammals (vertebrate animals with mammary glands) are viviparous. The inequalities to this rule are the echidnas and the platypuses, which are born in eggs that were previously inside the body of the pregnant female and that makes them ovoviviparous.
Examples of viviparous animals
There are extraordinary exceptions like the salamander of the subspecies Salamandra salamandra gallica, generally all viviparous are mammals. This is a list with different examples:
- Wild pig
They are those that form inside an egg, a dominated structure that can be inside or outside the body of the gestating animal.
Being inside an egg, the fetus cannot be nourished directly from the female, like viviparous animals. It feeds on the nutrients that the yolk has, when it has completed its development mission, it hatches, that is, it breaks the structure that retains it to go outside.
Examples of oviparous animals
Below we present all birds and most reptiles are oviparous.
- White stork
- Komodo dragon
- Shark (some species)
They are the animals that develop inside the womb but at the same time are inside an egg, and that share common characteristics with the viviparous and the oviparous. The egg can hatch inside the mother’s womb or be expelled at the time of birth.
They reproduce sexually by internal fertilization, since the creature has been formed, it begins to develop inside an egg, which in turn is contained inside the animal and where it will remain until its development process is complete.
Examples of ovoviviparous animals
Below we present all the ovoviviparous animals:
- crystal shingles
- Surinam Toad
- White shark
- Boa constrictor
|What are they?||They are animals that develop in the womb.||They form inside an egg.||They are animals that develop inside an egg that is inside the womb.|
|fetal nutrition||Through the placenta (placentotrophic).||They feed on the content of the egg (lecithotrophic).||Through the placenta (placentotrophic).
With the content of the egg (lecithotrophic).
|How are they born?||The creature is born when it is fully grown (except marsupials).||When the little animal is ready to be born, it breaks the shell.||When the calf completes its stage of development, the mother removes it from her body.|