How Do Sharks Give Birth? Complete Reproduction Process Explained

Sharks are regarded as large fish, and they are cold-blooded marine animals that breathe through fins, just like every other fish in water.

However, a key difference between sharks and fish is a bony fish has a single gill slit to breathe, whereas most sharks have five-gill slits. There are many species of sharks on this planet, and this is shown by the different places sharks live and their varying body sizes.

Sharks live all over the world ranging from the freezing waters of the polar seas to warm tropical lagoons. The largest shark species on Earth is the whale shark which is around 45 ft (14 m) long, whereas the smallest species is merely 8.7-9.8 in (22-25 cm) long. This diversity is exhibited even in a shark's reproduction methods. Many sharks lay eggs, while some choose the method of live birth. Sharks which lay eggs during gestation are known as oviparous sharks and those that undertake the method of live birth are called viviparous sharks. Interestingly, sharks are some of these rare animals that usually undertake sexual reproduction but can reproduce asexually as well. Research has been conducted and it was recorded that female sharks like zebra sharks, bonnetheads, and blacktips sharks were capable of giving birth to pups without the involvement of male sharks.

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What sharks lay eggs?

Although sharks share a number of characteristics with fish, they do not give birth to many pups. Unlike fish that lay eggs in large numbers. Not a lot of marine animals can lay eggs, as well as give birth to live pups, but sharks can depending on the species. Some sharks follow the egg-laying process for shark reproduction, and there are different species of these apex predators that undertake this method.

Around 40% of all sharks in the world are oviparous species, meaning they give birth to baby sharks by laying eggs. Once female sharks lay eggs, they do not really look after their babies.This is because a baby shark is present inside its own protective egg case. Baby sharks receive all the required nourishment from the yolk sac inside the egg case. The egg cases of sharks are not the typical eggshells you might be imagining, and there is a reason why they are called a 'mermaid's purse'. Some of these egg cases often get washed up and reach the seashore. When people take a look at them, they look pretty exquisite and have now ended up earning the name, 'mermaid's purses'.

Some shark species that use the method of laying eggs during shark reproduction include bullhead sharks, small-spotted catsharks, swell sharks, coral catsharks, gray bamboo sharks, and graceful catsharks. Whether it is for laying eggs or giving birth to a live baby shark, a female shark usually goes through the process of internal fertilization where a male shark inserts his claspers into the reproductive tract of the female shark for depositing sperm. Once mated, pregnant females either lay eggs in a short period of time or let them develop inside them. In some cases, shark pups even hatch inside, depending upon the shark species.

What sharks give birth to live young?

The shark reproduction method of giving birth to live young ones is undertaken by most shark species. However, there are other species that are oviparous and the former method is believed to be the most advanced one. Interestingly, sharks are some of the few predators that are a lot like humans when it comes to taking care of their babies during their pregnancies. At the same time, there are a lot of differences too. Sharks usually have very long gestation periods, some sharks have gestation periods of up to two years, and some other sharks have gestation periods stretching up to three years!

This method of increasing shark populations by giving birth to live young sharks is known as viviparity. In oviparity, baby sharks get all the required nutrients and other nourishment from the yolk sac but in the case of viviparity, there is an umbilical cord that connects the baby shark with its mother. The placenta present in the mother's body transfers all the nutrients and oxygen to the baby shark inside it from the mother's bloodstream and at the same time transfers out all the waste products.

These viviparous sharks such as lemon sharks, bull sharks, hammerhead sharks, and whale sharks give birth to a large number of pups at one time. On some occasions, these female predators have been found pregnant with around 100 little pups inside them. Interestingly, there is a third method of reproduction in sharks like in the case of the Greenland shark, the nurse shark, the sand tiger shark, the great white shark, and the tiger shark. These sharks are ovoviviparous. This means that in a female shark, the eggs hatch inside the mother shark and they develop inside the body of their mother, but not by using the placenta. They eat the unfertilized eggs presents within the body of the mother. This kind of sibling cannibalism is the reason why great white sharks or sand tiger sharks do not have a large population as only a few of these potential large predators survive.

How many babies do sharks have?

Currently, humans know that there are more than 400-500 species of sharks on this planet so it is no surprise that there are multiple methods of giving birth to shark pups. The first one is by laying eggs, and the second one is giving live birth just like humans. The third is a unique practice where a pup develops inside by feeding on unfertilized eggs.

The number of babies sharks can have at a time largely depends on the shark species. Those that follow the ovoviviparous method of reproduction have fewer young ones as sibling cannibalism leads to a reduction in the number of pups. Researchers say that a shark can give birth to 1-100 or more babies in one go, however it all depends on the type of shark. Once the babies are born, mother sharks do not care about them at all as their pups are born with teeth and are independent the very moment they are born.

How many eggs do sharks lay?

The oviparous method of reproduction is undertaken by only some shark species. The egg cases have the yolk sac in them, providing all the required nutrients to a baby shark for developing until it has hatched.

Some studies say that on an average sharks lay around 20 eggs a year. The leather-like cases in which they lay eggs often wash up on the sand and are known as 'mermaid's purses' due to their attractive looks. These cases also have tendrils attached to them so that they can be tied with the seaweed present on the sea bed.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked learning about how do sharks give birth, then why not take a look at how do jellyfish eat, or how do birds fly?