Livebearing Animals - Examples and Characteristics

Author: Peter Berry
Date Of Creation: 14 February 2021
Update Date: 6 November 2024
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Viviparity is a form of reproduction which is found in most mammals, in addition to some reptiles, fish and amphibians. Viviparous animals are animals that are born from the womb of their mothers. Humans, for example, are livebearers.

After a female mate or has a sexual union with a male of the same species, a new being can be formed, which at the end of a gestation process, will inherit the characteristics of its parents.

Continue reading this PeritoAnimal article in which we will detail Viviparous Animals - Examples and Characteristics. Good reading.

What are livebearers

Viviparous animals are those that carry out their embryonic development in the parent's uterus, receiving through it the necessary oxygen and nutrients until the moment of birth, when they are considered as fully formed and developed. Therefore, we can say that they are animals that are born from the mother's womb, and not from eggs, which are oviparous animals.


Embryonic development in animals

To really understand what livebearing animals are, it is essential to talk about embryonic development, which is the period from fertilization to the birth of a new individual. Thus, in the sexual reproduction of animals, we can differentiate three types of embryonic development:

  • Lively animals: after internal fertilization, embryos develop within a specialized structure of the parent's body, which protects and nourishes them until they are fully formed and ready to give birth.
  • Oviparous animals: in this case, internal fertilization also takes place, however, the development of the embryo takes place outside the mother's body, inside an egg.
  • Ovoviviparous animals: also through internal fertilization, the embryos of ovoviviparous animals develop inside an egg, although in this case the egg also resides inside the parent's body, until hatching occurs and, therefore, the birth of the offspring.

Types of reproduction of livebearers

In addition to differentiating the different types of embryonic development, we should know that there are different types of reproduction among livebearers:


  • Liver placental animals: they are those that develop within the placenta, an organ attached to the uterus that extends during pregnancy to make room for fetuses. An example would be the human being.
  • Marsupial viviparous: unlike other mammals, marsupials are born undeveloped and end up forming inside the marsupium, an external pouch that fulfills a function similar to the placenta. The best known example of a marsupial viviparous animal is the kangaroo.
  • Ovoviviparous: it is a mix between viviparism and oviparism. In this case, the mother lays the eggs inside her body, where they will develop until they are fully formed. Young people can be born inside the mother's body or outside it.

Characteristics of livebearers

1. Pregnancy system

Viviparous animals differ from oviparous animals that lay "external" eggs, such as most birds and reptiles. Viviparous animals have a more evolved and developed gestation system than oviparous animals, called placental viviparism, that is, those animals whose fetus graduates in a bag "placenta" inside the mother until the mother is mature, big and strong enough to be born and survive by itself outside the body.


2. Placenta

Another important feature is that developing viviparous animals lack a hard outer shell. The placenta is a membranous organ that contains a rich and powerful blood supply that surrounds the uterus of pregnant females. The fetus is fed through a supply line called umbilical cord. The time between fertilization and birth of the viviparous is called the gestation period or gestation and varies depending on the species.

3. Changes in the body

One of the most important aspects among mammals as live-bearing animals is the important transition that females undergo after an egg is fertilized, where the period of gestation or pregnancy begins. At this stage, the uterus increases in size in proportion to the growth of the zygote, and the female begins to experience a series of both internal and external changes in perfect natural preparation for this entire process.

4. Quadrupeds

The vast majority of viviparous animals are quadrupeds, this means that need four legs to stand, walk and move around.

5. Maternal instinct

Most mothers among mammals have a strong, narrow maternal instinct to feed and protect their offspring until they can survive on their own. The female will know exactly when that moment will happen.

6. Marsupials

In the animal world there is also another form of viviparism, this being the least common. We are talking about marsupials, such as the kangaroo.Marsupials are creatures that give birth to their offspring in an immature state and then receive the offspring in the bags they have in their abdomen where they nurse them. The cubs remain in this place until they are fully formed and do not need any more milk from their mother to survive.

Examples of Viviparous Animals - Viviparous Mammals

Now that you know what viviparous animals are, we point out that almost all mammals are viviparous. There are only a few exceptions of oviparous mammals, called monotremes, whose main representatives are the echidna and the platypus.

Examples of Viviparous Land Mammals

  • Dog
  • Cat
  • rabbit
  • Horse
  • cow
  • Pig
  • Giraffe
  • Leon
  • Chimpanzee
  • Elephant

Examples of viviparous aquatic mammals:

  • Dolphin
  • Whale
  • sperm whale
  • orca
  • Narwhal

Example of a viviparous flying mammal:

  • Bat

Examples of livebearing animals - livebearing fish

Among the most common viviparous fish - although technically they are ovoviviparous animals - there are species of guppies, platys or molineses:

  • reticulata Poecilia
  • Poecilia sphenops
  • wingei poetry
  • Xiphophorus maculatus
  • Xiphophorus helleri
  • Dermogenys pusillus
  • Nomorhamphus liemi

Examples of Viviparous Animals - Viviparous Amphibians

As in the previous case, the live amphibians are not particularly common, but we find two representative animals in the Caudata order:

  • merman
  • Salamander

Now that you know what livebearers are and know their main characteristics, you might be interested in this other article on generational alternation in animals.

If you want to read more articles similar to Livebearing Animals - Examples and Characteristics, we recommend that you enter our Curiosities section of the animal world.