Viviparity is a form of reproduction found in most mammals, as well as in some reptiles, fish and amphibians. Viviparous animals give birth to juveniles that have been fed and developed in direct contact with their mother’s body. Even humans are viviparous animals.
After mating or sexual interning of a female with the male of the same species, a new being may be born, which at the end of a gestation process will inherit the characteristics of its parents.
- Continue lendo este artigo do Perito Animal onde lhe mostramos os animais vivíparos com vários exemplos e características.
1- Viviparous animals are different from oviparous animals that lay “external” eggs, like most birds and reptiles. Viviparous animals have a more evolved and developed gestation system than oviparous, called placental viviparism, that is, animals whose fetus forms inside a “placenta” bag within the mother until it reaches sufficient maturity, is large and strong to be born and survive only outside the body.
2- Another important feature is that the eggs of viviparous animals are devoid of a hard outer shell or shell, such as a hen’s egg or other viviparous animals. In many cases, developing fetuses of viviparous animals are linked to a placenta in the mother’s body, which is a kind of egg. The placenta is a membrane organ that contains rich and powerful blood supply that surrounds the uterus of pregnant women. The fetus is fed through a feeding line called an umbilical cord. The time between fertilization and birth of viviparous people is called gestation or gestation period and varies by species.
3- Among the most important aspects in mammals such as viviparous animals is the important transition that females experience after the fertilization of an egg, where gestation or gestation period begins. At this point, the size of the uterus increases in proportion to the growth of the zygote, and the female begins to undergo a series of changes both internal and external in a perfect natural preparation for this whole process.
4- The vast majority of viviparous animals are quadrupedal, which means they need four legs to stand, walk and move.
5- Most mothers have a strong and close maternal instinct to feed and protect their young until they can survive on their own. The female will know exactly when that moment will happen.
6- In the animal world there is also another form of viviparism, which is the least common. We’re talking about marsupials, like the kangaroo. Marsupials are creatures that give birth to their young in an immature state and then receive them in the pockets of their abdomen where they feed them. The cubs stay there until they are fully formed and do not need more milk from their mother to survive.
Almost all mammals are viviparous, there are only exceptions for oviparous mammals, called monotrs whose representatives are echidate and ornitorrinco. In this group we must also include marine species such as dolphins, whales and narwhals, as well as the only flying mammal species: the bat. Special among all the animals in the world.
The most common viviparous are most pets: dogs, cats and rabbits. The farm animals are considered: horses, cows, pigs. And among the wild viviparous animals, we have giraffes, lions, chimpanzees and elephants.
So far, not many species of viviparous fish have been discovered, but to our surprise, there are some like guppys and muines.
There are also not many viviparous amphibians, however, we have some exceptions such as newts and salamanders.
Although most reptiles are oviparous, this group of viviparouss only find certain species of lizards and snakes (constrictor boa, sea snake, rattles, among others).
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