Oviparous and Viviparous Animal

Viviparous animals give birth to their kind while oviparous animals lay eggs. Tap to know more.

Difference between Oviparous and Viviparous Animal

OVIPAROUS ANIMALS VIVIPAROUS ANIMALS

Produce eggs that are expelled from the body.

Give birth to live, young animals of their species.

The eggs laid can either be fertilised or unfertilised.

They do not lay eggs. They give birth to individuals.

They undergo either internal fertilisation or external fertilisation.

They always undergo internal fertilisation. No external fertilisation occurs.

The zygote develops outside the body of the female.

The zygote develops inside the body of the female.

The embryo develops outside the body of the mother. Therefore, gets its nutrient from the yolk present in the egg.

The embryo develops inside the mother. Therefore it receives its nutrient from the mother itself.

The chances of survival of the eggs are less.

The chances of survival of the newborn are more.

Oviparous animals do not have mammary glands.

Viviparous animals have mammary glands.

Need to hide their eggs to protect them from predators.

They can move their young ones to protect them from predators.

Need to develop yolk sac during their high intake of food as the embryo derives nutrition from the yolk.

Have the ability to nourish the embryo by the stored fat in the mother’s body.

Lay eggs during their high food intake.

Can reproduce throughout the year.

Oviparous animals include birds, reptiles, amphibians, most fishes, insects.

Viviparous animals include mammals.

Viviparous Animal

Viviparous animals are the animals that give birth to developed live individuals of their kind. The mother’s body has a special organ in which the embryos are developed before being expelled from the body. These organs also supply nutrients, gases, and other substances necessary for the embryo to survive and develop. This condition is known as matrotrophy. Viviparous animals exist in almost vertebra texa while there are very few in the invertreba taxa. According to some theories, the ability to reproduce viviparously is derived from oviparous animals. Viviparous animals reproduce sexually. They form embryos through internal fertilization. The males must have organs necessary to fertilize the females, for example, mammals have a penis, sharks have claspers, or the gel-like structures possessed by salamanders which they leave outside their body to be found by the females. Birds are the only group of animals that do not have any viviparous animals. The theory behind this is the way the birds have evolved. The birds became endothermic during their early evolutionary periods. The viviparous animals can move their young ones. This ability helps them to survive in areas with predators. Viviparous animals can give birth at any time of the year. Viviparous can nourish their young ones through their reserved fat in the body. This ability of these animals allows them to reproduce any time of the year.

Example of Viviparous Animal

Humans- humans reproduce via internal fertilization. In higher mammals, the egg is implanted in the fallopian tube while it develops in the uterus. The embryo receives its nutrition from the placenta. Humans are born way before their full development

Sharks- sharks such as great white sharks have tissues similar to the placenta of humans. The exchange of nutrients is in the form of a milky substance. After being born into the environment, they start eating their prey right away

Amphibians- salamanders, and frogs reproduce using this method. The oviducts nourish the eggs and transport them to the cloaca. The young embryos scrape the surface of the oviduct by using embryonic teeth which signals the oviduct to produce a nutritive substance that nourishes it until its born

Oviparous animals

Oviparous animals are the animals that give birth to their young ones indirectly by laying eggs. These animals may undergo external or internal fertilization but the development of the zygote always occurs outside the body of the mother. Many oviparous animals make nests to protect their eggs. Oviparity is a reproductional strategy pf evolution. According to this, one or many eggs can be produced, each egg representing a gamete. The eggs laid by the oviparous can either be small, fragile, and large in number or large, strong, and few. The oviparous animals must hide their eggs to protect them from predators. Some oviparous animals sit on their eggs to keep them warm or even constantly like penguins in cold climatic countries.

Examples of Oviparous Animals

Birds- all birds are oviparous. In general, they lay eggs that have hard shells and have been fertilised internally

Reptiles- their eggs mostly have soft shells. The eggs are incubated in nests. Reptiles bury their eggs to keep them warm. The sex of the egg depends on the temperature during certain periods of the development of the embryo. This is called temperature-dependent sex determination

Fish and Amphibian- many fish show external fertilisation. Fertilisation in amphibians is also mostly external. They often emerge as a larva that develop into adults through metamorphosis

Conclusion

Oviparous and viviparous animals produce offspring differently. The oviparous animals reproduce by laying eggs and viviparous animals reproduce by giving birth to young ones. Some animals are ovoviviparous i.e. they lay eggs but the egg is developed inside the mother’s body. Platypus is the only mammal to reproduce oviparously.