With hundreds of different kinds of sharks in our oceans, it’s no surprise that there’s a diversity in reproduction methods among the different species. Most other fish lay eggs, so do sharks lay eggs? This is a question we are about to answer.
What Are Some Sharks that Give Birth to Live Young? (Also Called Viviparity)
These sharks are viviparous:
- Hammerhead Sharks
- Blue Sharks
- Lemon Sharks
- Silvertip Shark
- Salmon Shark
- Bull Sharks
- White-Tip Reef Sharks
Do Sharks Lay Eggs?
Some sharks lay eggs, but most sharks have eggs inside their body that they incubate until they’re hatched. They then birth the hatched young into the ocean. Some sharks give birth to live young in a way like the process that mammals undergo.
No matter how a shark is born or hatched, it is born independent. A shark baby is known as a pup,, and those that are born swim away from their mother as fast as they can to avoid being eaten.
We will look at some details about shark eggs and pups below.
What Are Some Sharks that Lay Eggs? (Also Called Oviparity)
These sharks are oviparous:
- Cat Sharks
- Horn Sharks
- Bamboo Sharks
- Carpet Sharks
- Zebra Sharks
- Swell Sharks
- Port Jackson Shark
- Dogfish Sharks
- Australian Swellshark
What Are Some Sharks that Lay Internal Eggs and Give Birth? (Also Called Ovoviviparity)
These sharks are ovoviviparous:
What Does a Shark Egg Look Like?
An oviparous shark’s egg has a casing around it when it is laid. The mother shark puts these eggs in places she thinks will be safe using the tendrils on the egg case itself. These tendrils and the horns on the egg casing that they come from vary in appearance depending on the shark.
This egg case protects the embryo and yolk from some predators because it’s thick and leathery. The embryo can usually be seen wriggling inside.
The casings themselves are made of keratin which is the same fibrous protein found in human fingernails and hair. When the pup is ready to enter the world, it chews a hole into the egg casing to get out.
What is a Mermaid’s Purse?
A mermaid’s purse is a shark egg case that washes up on a shore. It looks a lot like seaweed when it is on the beach.
Each shark produces a slightly different mermaid’s purse, so it’s possible to identify the original shark species just from this casing. Rays, chimeras, and skates also create egg cases similar in appearance to a shark casing. These are also colloquially known as a mermaid’s purse.
Do Sharks Nurse Their Pups?
No, sharks do not nurse their pups. A shark is born as a fully independent miniature adult.
Some sharks release milk into their uterus during gestation. This usually happens in ovoviviparous sharks once the pups have hatched but before they’re birthed.
Which Sharks Produce Spiraled Eggs?
Bullhead sharks, Port Jackson sharks, and horn sharks are sharks that produce spiraled eggs. They’re intended to be screwed into rocky areas or in areas with more turbulent waters that won’t work with the tendrils of traditional egg cases.
The eggs are spiraled to make them harder to crack into, but this doesn’t stop some seals and snails. The snails probe through the shell and eat the yolk, so despite how specialized they are, spiraled eggs can still make a good snack for some animals.
Can You Eat Shark Eggs?
Yes, you can eat unfertilized shark eggs. They can be found in females fished out of the sea or at your local fishmonger, if you can find a retailer that sells shark whole. Buying a shark whole is akin to buying a whole pig to roast, so you’re better off finding eggs in freshly fished catches unless you’re trying to throw a huge party.
While oviparous shark eggs with mermaid’s purses are not edible, the unfertilized eggs found in sharks killed for other reasons are considered a treat to some.
Some of these eggs can be large at about the size of a chicken’s egg. They are often pan-fried. Shark meat, which is a byproduct of the fishing industry, is also eaten around the world in a variety of preparations.
Monkeys in some areas are known to eat the contents of a shark’s egg casing if they’re near the water and the tide at its lowest point. They crack open the casing with their sharp front teeth and pull out the shark and yolk sac inside.
Do Shark Pups Eat Each Other?
Some ovoviviparous shark pups cannibalize each other in the womb. The sand tiger shark creates a bunch of eggs in two uteri. As the eggs hatch,but before they are born, they begin developing teeth.
Those that develop teeth first make a meal out of their smaller siblings and unhatched eggs. Only two pups remain come their birthday: one from each uterus. This form of cannibalism is known as adelphophagy.
Adelphophagy in tiger sharks probably occurs because pups from different fathers are competing. It’s a paternity battle in the womb.
Another cannibalistic practice involves sharks in utero eating the unfertilized eggs around them. This is called oophagy. It’s estimated that 15 or so species of sharks practice this form of cannibalism.
Some ovoviviparous mothers keep producing unfertilized eggs for their babies throughout gestation. Research suggests that a shark’s teeth develop most during this egg-eating phase.
Why are Mangroves an Important Habitat for Pups?
Mangrove forests are dense forests made from plants adapted to tidal waters. Their thick roots create an underwater labyrinth in the shallow water that captures sediments and traps small animals within the maze created.
It’s an ecosystem separate from other coastal environments because of the littered bottom and ability to hide. It makes the perfect place for certain shark species to deposit their eggs or their young so they can hunt small prey and protect themselves until they’re big enough to venture out into the open ocean.
Since sharks pups are born fully independent, and most aren’t born with full stomachs, pups have to start searching for food almost immediately after birth. Crustaceans, crabs, and suitable size fry of other fish provide the perfect opportunity to snack away on the food required to keep growing.
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