How Do Sharks Give Birth?

Sharks have been fascinating people for hundreds of years, and one thing that’s really interesting about them is how they have babies. Most fish lay eggs, but sharks can give birth in three different ways: oviparity, ovoviviparity, or viviparity. This article is all about viviparity, which is when sharks give birth to live babies.

Viviparity: A Complex Reproductive Strategy

Viviparity is a way of having babies that lots of animals use, including some fish, reptiles, and mammals. When an animal is viviparous, the baby grows inside the mother’s body and gets food from her until it’s ready to be born. This is a complex process that needs a lot of changes in the mother’s body to make sure both she and the baby stay healthy.

Sharks that use viviparity have special things in their bodies to help their babies grow. One of the most important is the placenta, which lets the mother and baby exchange food and waste products. In some sharks, the placenta has unique structures that help exchange other things too, like gases and hormones.

Special Adaptations for Viviparous Sharks

Another special thing that some viviparous sharks do is called oophagy. This is when some of the baby sharks eat their brothers and sisters while they’re still in their mother’s body. It sounds scary, but it’s something that lots of animals do, including some mammals.

Gestation Period and Litter Size Variations

Different kinds of sharks have different lengths of time for their babies to grow before they’re born. Some, like blue sharks, only take nine months, while others, like spiny dogfish, can take up to 24 months. The number of babies born also changes a lot, with some sharks having just a few babies and others having more than 100.

Post-Birth Behaviors: Shark Mothers and Their Offspring

Sharks that give birth to live babies do things to help their babies survive after they’re born. Some swim in shallow water or near the surface so their babies can breathe oxygen, while others stay in one place for a long time to keep their babies safe.


In conclusion, how sharks have babies is a really cool thing to learn about. Viviparity is important for making sure baby sharks can survive and grow, and it lets sharks live in lots of different parts of the ocean. By studying how sharks have babies, we can learn more about these amazing creatures and how important they are to the ocean.