Oviparous and Viviparous Animals

Animals of different groups show different types of reproduction. Some lay eggs while some give birth to their young ones. In this concept, the students will understand the meaning of oviparous and viviparous animals.

After reading the concept, students will be able to:

• Know what is reproduction in animals.
• Mention the modes of reproduction.
• Define spawn.
• Recall which animals show the presence of mammary glands.
• Define what is offspring.
• Remember the examples of marsupial animals.
• Answer why the Platypus is an exception among mammal.

Each concept is explained to class 4 students using descriptions, illustrations, and concept maps. After you go through a concept, assess your learning by solving the two printable worksheets given at the end of the page.

Download the worksheets and check your answers with the worksheet solutions for the concept Viviparous and Oviparous Animals provided in PDF format.

Reproduction in Animals:

It is a process by which animals create their offspring. Reproduction helps animals produce babies of their kind. These babies may share the same characteristics as their parents. Reproduction helps an animal to increase its number in a specific habitat.

Modes of Reproduction:

There are two modes of reproduction—oviparity and viviparity.

• Animals that show oviparity are called oviparous animals.
• Animals that show viviparity are viviparous animals.

Oviparous Animals:

Animals that reproduce by laying eggs are called oviparous animals

Examples:Frog, fish, snake, crow etc.

Characteristics of Oviparous Animals:

• These animals lay eggs.
• The young hatches from the eggs after being expelled from the body.
• The mother sits on the eggs to keep them warm.
• Sometimes, the mother may dump their eggs and leave. In such cases, the eggs get warmth from the sunlight.
• The embryo resides within the egg and receives nourishment from it.
• Under proper conditions, the embryo matures, and the young one comes out of the egg by breaking its outer shell.
• This process is called hatching.

Examples:Insects, fish, amphibians, reptiles, birds.

Oviparity in Fish:

• Fish lay eggs in the water.
• Generally, the female fish lays eggs in batches.
• A single batch may contain thousands of eggs that are collectively called spawns.

Oviparity in Amphibians:

Amphibians, like frogs, lay eggs in the water.Amphibian eggs have no shell.They lay eggs in clutches.Later on, the mature embryo comes out of the egg under proper conditions.After the eggs are released from the body, they take up water and get bigger.

Oviparity in Reptiles:

Reptiles make holes in the ground and lay eggs in those holes.After laying eggs, the mother leaves and never comes back to nurture the babies.The eggs have shells, but the shells are leathery and elastic-like.The eggs get warmth and light from the sun, and when the embryo matures, it breaks the eggshell and comes out.

Oviparity in Birds:

Birds build their nests and then lay eggs in them.They sit on the eggs to keep them warm.Parents take care of their newly hatched chicks, feed them and stay with them until they mature and start flying.

Viviparous Animals:

Animals that reproduce by giving birth to young ones are called viviparous animals.

Examples:Man, elephant, monkey, cat, dog etc.

Characteristics of Viviparous Animals:

• Viviparous animals have body hair and have mammary glands.
• The babies feed on their mother’s milk.
• These animals have developed brains and external ears.
• In the case of all viviparous animals, babies develop inside their mother’s body.
• When the babies are born, they are nurtured by their mothers until they become mature enough to live independently.

Examples:Deer, elephant, horse, cow, cat, rat, kangaroo.

Types of Viviparous Animals:

Viviparous animals can be divided into two categories—

1. Marsupials: These animals have a pouch in their bodies where they carry their immature babies.

Examples:Opossum, kangaroo, koala.

2.Mammals: These animals have no pouch in their bodies instead they protect their babies outside the body.

Examples:Monkey, deer, tiger, dog, elephant.

 New Words:

Exception:One of the most unique animals in this world is the platypus. Despite being a mammal, it is adapted to survive in aquatic habitats and surprisingly lays eggs. The eggs hatch within two weeks, and the babies are nourished by their mother’s milk. So, the platypus is considered to be an oviparous mammal.