Depending on the way they reproduce, there are two large groups of animals: the viviparous and the oviparous:
- Viviparous animals. The offspring develops in the female’s reproductive system over a variable period of time and is finally born through the vaginal canal. Mammalian animals (including humans) typically fall into this category, although there are exceptions. For instance: rabbit, dog, kangaroo.
- Oviparous animals. The young are formed and developed inside an egg, which has been previously fertilized by the male of the species and laid by the female. For instance: frog, bee, parrot.
What are oviparous like?
In the case of oviparous animals, the fertilization it can occur inside or outside the female’s body. The development of the young, then, takes place outside the body of the mother. Oviparity is characteristic of birds, fish, and amphibians. Some reptiles, such as turtles and snakes, and many insects are also oviparous.
That the offspring develop within a egg It is considered an evolutionary advantage that tends to improve the survival rate, since the structure of the egg protects the embryo and prevents desiccation, which can be very relevant in warm regions.
There is a mixed category, which is that of ovoviviparous. In this case, the eggs remain inside the female’s body until the embryo is fully developed. Certain sharks and various invertebrate animals make up this category.
The oviparous and the care of their eggs
Not all oviparous animals handle their eggs in the same way. Almost all put them in nests. While birds often build their nests in trees or on the ground, where they hatch, other animals, such as turtles, bury their eggs in the sand.
The fishes and the amphibians, for his part, they lay their eggs in the water. Penguins also lay eggs. These eggs are generally covered by a gelatinous layer that protects them.
They are usually translucent and incubating quickly, from which the so-called fry emerge, which feed on the yolk sac of the egg.
Examples of oviparous