We explain what oviparous animals are and how these animals are classified. Also, the types of eggs and examples of oviparous.
What are oviparous animals?
Oviparous animals are those whose reproductive process includes egg deposition in a certain environment, within which the offspring complete their embryonic formation and maturation process, until later emerging as a formed individual.
The term oviparous It comes from the Latin: ovum, “Egg” and give birth, “give birth”, that is, it refers to animals that lay eggs. In this they differ from viviparous animals (such as humans), who give birth to their young, already fully formed, more or less ready for an independent existence.
There are two types of oviparous animals, according to their fertilization:
- Internally fertilized oviparous. Those that lay dry eggs, already fertilized, as the male fertilizes the female inside her body.
- Oviparous from external fertilization. Those in which the female deposits soft, unfertilized eggs in the environment, and then the male fertilizes them with his sperm.
It may be that an animal is ovoviviparous, that is, an intermediate category between viviparous and oviparous: its young are born from fertilized eggs inside the mother’s body, where they also hatch. The young then remain inside it until they mature and are expelled along with the egg residues.
Lyou different types of eggs
The number of eggs deposited and their physical characteristics vary enormously from one species to another, but are generally biologically adapted to ensure the survival of the new individual as much as possible.
That is why dry eggs have a resistant shell that hardens in contact with air, and that newborns must break from within to be born. Instead, wet eggs often possess specialized chemistry to adhere to surfaces and ward off predators.
Eggs may hatch shortly after laying or may require days or weeks of incubation.
Examples of oviparous animals
All of the following are oviparous animals:
- Sea and land turtles, some of which often migrate for miles to spawn.
- Reptiles of all kinds: iguanas, salamanders, crocodiles, Komodo dragons, chameleons, etc.
- Poisonous snakes (like Cobra, Rattlesnake, etc.) or constrictors (like Boas, Anaconda, etc.).
- Platypus and echidnas are the only oviparous mammals, since being extremely primitive they retain certain reptilian characteristics.
- The vast majority of fish, rays and eels are oviparous. There are very few exceptions. This does not include sharks, for example, which are ovoviviparous.
- All insects are oviparous: from beetles, butterflies and crickets, to the praying mantis or mosquitoes.
- Arachnids and crustaceans are also oviparous: crabs, spiders, scorpions, lobsters, etc.
- The birds in their entirety are oviparous, and usually guard their eggs in a nest made by themselves. It does not matter if they are large birds of prey or a simple hummingbird.
- Dinosaurs were entirely oviparous, from violent predators (such as Tyrannosaurus), large herbivores (such as Diplodocus) to the smallest (such as Compsognatus).