The Amazing Life Cycle of Sharks, Animal Sake

Sharks are the most feared predators in the ocean, and for good reason. These animals have been prowling the seas for around 400 million years and have evolved into 440 different species. But how do they actually grow up? Read on to find out all about the shark life cycle.

Sharks: Ancient Ocean Predators

Sharks are spread across all the world's seas and are the strongest predators among marine creatures. Most wild marine sharks can live for up to 20-30 years, while whale sharks have a remarkably long lifespan of up to 100 years. Sharks have excellent eyesight and can spot objects moving even in dim light. Their strong senses of smell and touch make them highly effective hunters. Once a shark has locked onto its prey, that animal has very little chance of escape.

Sharks have cartilage instead of heavy bones. This gives their bodies great flexibility, which helps them swim fast and change direction quickly. There are all kinds of sharks that have been prowling the ocean for millions of years, and they continue to fascinate scientists and nature lovers alike.

How Sharks Carry Their Young

Sharks carry their young in three different ways:

Oviparous, Some sharks lay eggs directly in the sea. Each egg has a tough, leathery case (sometimes called a "mermaid's purse") that protects the developing pup until it hatches. The shape of the egg case varies by species.
Viviparous, Certain sharks have a placenta, just like mammals. The mother feeds and nourishes the pup through the placenta throughout the pregnancy. The pups are born live into the sea at the end of the gestation period.
Ovoviviparous, Many sharks lay eggs inside their own bodies. After the eggs hatch, the pups stay inside the mother until they are fully developed. The mother provides complete nutrition throughout this time. Once the pups are ready, she gives birth to live young. The gestation period for these sharks can range from a few months to two years.

A shark egg case, also called a mermaid's purse, on the sandy seabed with a developing embryo visible inside — Shark egg cases are sometimes called "mermaid's purses." The tough outer casing protects the developing pup until it is ready to hatch.

Lives of Sharks

Life Cycle of Great White Sharks

The great white shark mainly lives in temperate waters and is usually spotted alone. These sharks grow up to 21 feet in length and weigh around 680 kg. Great whites feed on many marine animals, including porpoises, seals, sea turtles, and other small sharks. They are ovoviviparous. Females give birth to around 2-14 pups per litter. The gestation period is not fully known for ovoviviparous sharks like the great white.

Female great white sharks reach sexual maturity at around 12-14 years of age, while males mature earlier, at 9-10 years. Newborn great white pups measure up to 100 cm at birth and weigh about 40 pounds. Sometimes the developing pups even eat unfertilized eggs while still inside the mother.

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Life Cycle of Hammerhead Sharks

The unusually shaped hammerhead shark is known to live up to 30 years. These sharks are found in all the world's oceans and are excellent at tracking prey using their distinctively wide, flat heads. The female hammerhead produces a litter of 30-50 pups each year. Gestation lasts around 10-12 months. The pups separate from their mother soon after birth and move to shallow waters to start hunting on their own.

Hammerheads measure 13-20 feet in length and weigh around 500 to 1,000 lbs. They migrate to cooler waters each year and mainly feed on squids and octopuses.

A hammerhead shark swimming near a coral reef, its distinctive wide flat head clearly visible — The hammerhead's wide, flat head spreads its sensory organs apart, giving it an exceptionally wide field of vision to hunt prey.

Life Cycle of Bull Sharks

Bull sharks are aggressive and swim in shallow coastal waters, which means they sometimes come into contact with people. Female bull sharks are larger than males: females can reach 11.5 feet in length and weigh up to 500 pounds, while males grow to about 7 feet and weigh around 200 pounds. Bull sharks are viviparous, meaning they give birth to live pups. Females produce a litter of 1-13 pups, and the gestation period lasts up to a year. The pups are 28 inches long at birth, and bull sharks have a lifespan of about 15 years.

A stocky bull shark swimming in murky shallow coastal water, its thick body and blunt snout clearly visible — Bull sharks are among the most dangerous sharks to humans because they prefer shallow coastal and river waters where people swim.

Life Cycle of Thresher Sharks

Thresher sharks are ovoviviparous. Males reach sexual maturity when they grow to 2.7 meters, while females mature at 3 meters. A female thresher can give birth to 4-6 pups, each measuring around 1.37-1.55 meters in length and weighing about 5-6 kg at birth. The pups grow quickly once they enter the water. Thresher sharks live in warm waters and are sometimes seen in coastal areas hunting for food. On average, a thresher shark lives for up to 20 years or more.

A thresher shark in deep blue ocean water, its extraordinarily long tail fin extending behind it — The thresher shark's tail is its most distinctive feature, it can be as long as the rest of the body, and the shark uses it to stun schools of fish.

A World Shaped by Sharks

Sharks have been in existence for around 420 million years and have evolved into many different species over that time. A shark's physical appearance, diet, and habitat all shape its unique life cycle. Every species of shark has its own remarkable traits that make it one of the ocean's most extraordinary predators.

Term	What it means
Oviparous	Reproduces by laying eggs outside the body. The eggs develop and hatch in the environment (e.g. on the seabed).
Viviparous	Gives birth to live young that developed inside the mother, nourished through a placenta, similar to how humans and most mammals reproduce.
Ovoviviparous	Eggs hatch inside the mother's body, and the pups continue to develop there until they are born live. No placenta, pups may eat unfertilized eggs for nutrition.
Cartilage	A tough but flexible tissue that makes up a shark's entire skeleton. It is lighter and more bendable than bone, helping sharks swim efficiently.
Gestation period	The time a baby animal spends developing inside its mother before birth. In sharks this ranges from a few months up to two years depending on the species.
Sexual maturity	The age at which an animal is old enough to reproduce. Great white females reach maturity at 12-14 years; males at 9-10 years.

The Amazing Life Cycle of the Most Feared and Dangerous Sharks

Sharks: Ancient Ocean Predators

How Sharks Carry Their Young