What Are Oviparous Animals
We explain what oviparous animals are and how these animals are classified. In addition, types of eggs and examples of oviparous.
Oviparous animals are characterized by laying eggs.
Oviparous animals are those whose reproductive process includes the deposition of eggs in a certain environment, within which the young culminates their process of embryonic formation and maturation, until they later emerge as a formed individual.
The term oviparous comes from the Latin: ovum, “egg” and parire, “to give birth”, that is, it refers to the animals that lay eggs. In this they differ from viviparous animals (such as the human being himself), which give birth to their fully formed offspring, more or less ready for an independent existence.
There are two types of oviparous animals, according to their fertilization:
- Internal fertilization oviparous. Those that deposit dry eggs, already fertilized, because the male fertilizes the female inside her body.
- External fertilization oviparous. Those in which the female deposits soft, unfertilized eggs in the environment, and then the male fertilizes them with his sperm.
An animal may be ovoviviparous, i.e. an intermediate category between viviparous and oviparous: its offspring are born from fertilized eggs inside the mother’s body, where they also hatch. The hatchlings then remain inside it until they mature and are expelled along with the egg residues.
The different types of eggs
The amount of eggs laid and their physical characteristics vary greatly from species to species, but they are generally biologically adapted to ensure as much as possible the survival of the new individual.
That’s why dried eggs have a tough shell that hardens in contact with air, and that newborns must break from the inside to be born. Wet eggs, on the other hand, often have a specialized chemistry to adhere to surfaces and shy away from 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 miles for spawning.
- Reptiles of all kinds: iguanas, salamanders, crocodiles, Komodo dragons, chameleons, etc..
- Poisonous snakes (such as the Cobra, the Rattlesnake, etc.) or constrictors (such as the Boas, the Anaconda, etc.).
- The platypus and echidnas are the only oviparous mammals, as they are extremely primitive and retain certain reptilian characteristics.
- Fish, rays and eels are mostly 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 religious mantises or mosquitoes.
- Arachnids and crustaceans are also oviparous: crabs, spiders, scorpions, lobsters, etc.
- All birds are oviparous, and they usually keep their eggs in a nest made by themselves. It doesn’t matter if they’re big birds of prey or just a hummingbird.
- Dinosaurs were oviparous in their entirety, from violent predators (such as the Tyrannosaurus), large herbivores (such as the Diplodocus) to the smallest (such as the Compsognatus).