Viviparous, oviparous, and ovoviviparous animals differ in that viviparous develop in the mother’s womb, oviparous in an egg that grows outside the womb, and ovoviviparous in an egg as well, but inside the mother’s womb.
| viviparous | oviparous | Ovoviviparous | |
|---|---|---|---|
| Which are | They are animals that are formed in the mother’s womb. | They are animals that form inside an egg. | They are animals that form inside an egg that is inside the mother’s womb. |
| Fetal nutrition | Through the placenta (placentotrophic). | They feed on the contents of the egg (lecithotrophic). |
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| How they are born | The young are born when they are fully formed (except marsupials). | When the baby is ready to be born, it breaks the shell. | When the baby completes the development process, the mother expels it from the body. |
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What are viviparous animals?
Viviparous animals are all those that develop and feed inside the body of the pregnant female until the moment of birth. Once they are born, they can live independently as they are fully developed.
An exception to this rule are viviparous marsupials, whose young are born at a premature stage and need to complete their formation process inside the pouch of the parent animal (such as kangaroos).
Almost all mammals (vertebrate animals with mammary glands) are viviparous. The exceptions to this rule are echidnas and platypuses, which are born in eggs that were previously inside the parent female’s body, making them ovoviviparous.
The term viviparous comes from Latin viviparouswhich is at the same time a word composed of alive (alive, animated, with life) i give birth (give birth, give birth).
How do viviparous animals reproduce?
Viviparous animals reproduce sexually. Fertilization occurs when the male’s sperm unites with the female’s egg and an embryo is generated. Depending on how the evolution of the embryo continues, viviparous are classified into two types:
- Placental viviparous: pregnant females have a placenta where the embryo will complete the development process until the time of birth.
- Viviparous marsupials: Pregnant females do not have a placenta, so the embryo can only develop to a certain extent. At birth, it passes into the marsupium, an outer pouch-like structure, where it will complete its development.
Fetal nutrition of viviparous animals
The fetal nutrition of viviparous is placentotrophic, that is to say, they feed through the maternal placenta. These nutrients depend directly on the mother’s diet. Therefore, a well-nourished live female will give birth to a well-nourished embryo.
The gestation process varies by species. Gestation lasts 20 days in mice, nine months in humans and 12 to 18 months in whales.
Examples of viviparous animals
Except for extraordinary exceptions, such as the salamander of the subspecies Salamander Gallic salamander, almost all viviparous are mammals. Here is a list with some examples:
- kangaroo
- tiger
- Whale
- Lion
- bear
- dog
- rabbit
- cat
- gazelle
- Zebra
- horse
- dolphin
- pork
- giraffe
- rhinoceros
- sheep
- goat
- cow
- wild boar
- gang bear
What are oviparous animals?
Oviparous animals are those that develop inside an egg, a specialized structure that can be inside or outside the body of the gestating animal.
Because it is inside an egg, the embryo cannot feed directly from the parent female, like viviparous. In this case, it feeds on the nutrients that the yolk has. When it has completed the development process, it hatches, that is, it breaks the structure that contains it to go outside. This process is usually instinctive, so the baby does not require help to be born.
Birds, insects and most reptiles, fish and amphibians are oviparous, with a few exceptions of ovoviviparous species.
Ovípar comes from the Latin compound for ovum (egg) i give birth (give birth).
How do oviparous animals reproduce?
In oviparous, reproduction can be internal or external. This involves two different types of egg development:
- Internal fertilization: after the copulation between the male and the female, an embryo is generated inside it. The female will then lay an egg containing the embryo and deposit it in a safe place (in a nest, under the sand, in a hidden place, etc.). In this egg, the future brood will complete its development until it is time to hatch and be born.
- External fertilization: the female expels an egg outside, which will be fertilized by the male. From there, it will evolve until hatching time.
Fetal nutrition of the oviparous
The nutrition of oviparous embryos is lecithotrophic. This means that the embryos feed exclusively on the nutrients found in the yolk.
Egg care
The quantity and care of the eggs depends on each species. A farm hen can lay one egg a day, while a sea turtle can lay more than 70 eggs from a single fertilization.
On the other hand, both male and female penguins take part in the care of the eggs to avoid exposing them to predators. Other species lay eggs and abandon them, such as lizards and most reptiles.
Examples of oviparous animals
All birds and most reptiles are oviparous. Here are some examples:
- penguin
- ant
- white stork
- Parrot
- hen
- ostrich
- iguana
- eagle
- Condor
- frog
- sparrow
- Komodo dragon
- Macaw
- Turtle
- Shark (some species)
- crocodile
- Bee
- toad
What are ovoviviparous animals?
Ovoviviparous are those animals that grow inside the pregnant womb, but at the same time are inside an egg, so they share common characteristics with viviparous and oviparous. The egg can hatch inside the mother’s womb or be expelled at birth.
How do ovoviviparous reproduce?
Ovoviviparous reproduce sexually by internal fertilization. When the embryo has formed, it begins to develop inside an egg, which is also contained inside the pregnant animal, where it will remain until the development process is completed.
The nutrition of future ovoviviparous offspring can be:
- Placentotrophic: the embryo is nourished through the mother’s placenta, like viviparous.
- lecithotrophic: the embryo is nourished by the nutrients contained in the egg, like the oviparous.
Examples of ovoviviparous animals
Here are some examples of ovoviviparous animals:
- Mantarratlla
- platypus
- echidnas
- Glass culvert
- Surinam toad
- White shark
- Melga
- triocers
- good constrictor
- Anaconda
You may be interested in knowing the difference between vertebrate and invertebrate animals.