We explain what oviparous animals are and how these animals are classified. In addition, the types of eggs and examples of oviparous.
What are oviparous animals?
Oviparous animals are those whose reproductive process includes the deposition of eggs in a certain environment , within which the offspring culminate their embryonic formation and maturation process, until they subsequently emerge as a trained individual.
The term oviparous comes from the Latin: ovum , “egg” and parire , “to give birth” , that is, refers to the animals that lay eggs. In this they differ from viviparous animals (like the human being itself ), who give birth to their already fully formed offspring, more or less ready for an independent existence.
There are two types of oviparous animals, according to their fertilization:
- Oviparous internal fecundation . Those who deposit dried eggs, already fertilized, because the male fertilizes the female inside his body.
- Oviparous external fertilization . Those in which the female deposits soft eggs in the environment, without fertilizing, and then the male fertilizes them with his sperm.
It can be that an animal is ovoviviparous, that is, an intermediate category between viviparous and oviparous: its offspring are born from fertilized eggs within the mother’s body, where they also hatch. The young then remain inside it until they mature and be expelled along with the egg residues.
Different types of eggs
The amount of eggs deposited and their physical characteristics vary greatly between one species and the other, but they are generally biologically adapted to ensure as much as possible the survival of the new individual.
That is why dried eggs have a resistant shell that hardens in contact with the air , and that newborns must break from the inside to be born. In contrast, wet eggs often have specialized chemistry to adhere to surfaces and avoid predators.
Eggs may hatch shortly after laying or may require days or weeks of incubation.
Examples of oviparous animals
The following are oviparous animals:
- Sea and land turtles, some of which usually migrate kilometers for spawning.
- Reptiles of all kinds: iguanas, salamanders, crocodiles, Komodo dragons, chameleons, etc.
- Poisonous snakes (such as Cobra, Rattlesnake, etc.) or constrictors (such as Boas, Anaconda, etc.).
- The platypus and echidnas are the only oviparous mammals, since being extremely primitive they retain certain reptilian characteristics.
- The 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 the praying mantis or mosquitoes.
- Also arachnids and crustaceans are oviparous: crabs, spiders, scorpions, lobsters, etc.
- The birds as a whole are oviparous, and tend to guard their eggs in a nest made by themselves. It doesn’t matter if they are large birds of prey or a simple hummingbird.
- Dinosaurs were oviparous in their entirety, from violent predators (such as the Tyrannosaurus), large herbivores (such as Diplodocus) to smaller ones (such as Compsognatus).