Category Plants & Animals

People kill millions of sharks every year, some to protect swimmers, others for food or just for sport. If too many are killed, sharks might disappear altogether.

How can we learn more about sharks?

These days, people are more keen to learn about sharks. You can visit an aquarium to watch and find out more about these fascinating fish.

Amazing! Scientists can now tell a lot from some sharks’ behaviour. By studying a creature’s movements and senses, they know when a shark is just being nosy, or when it’s about to attack. By learning more, we may kill fewer sharks, and suffer fewer shark attacks.

Which scientists dress like knights of old?

Scientists studying sharks sometimes wear chain-mail suits for protection. They may tag a shark’s fins to learn how quickly and far it can travel.

Is it true? We’ve discovered all the sharks that exist.

No. Megamouth was first seen in 1976. Scientists think that there might be more sharks waiting to be discovered in the depths of the oceans.

Goblin sharks were discovered 100 years ago and yet we still know very little about them. They live in deep water, and use their long, sensitive snouts to seek out prey.

What has a head like a hammer?

The head of a hammerhead shark is spread out to form a T-shape with its body. Its eyes are on each end of the ‘hammer’. As it swims, it swings its head from side to side so it can look around.

What bites chunks out of its prey?

Cookiecutter sharks are often happy with just a bite or two from their prey, which includes whales, seals and dolphins. The wounds they make with their small teeth are oval-shaped, a bit like a cookie.

Is it true? Cookiecutter sharks can glow.

Yes. These small sharks have light organs on their undersides, which glow, maybe to persuade their prey to come close to them.

Amazing! Hammerhead sharks have few enemies and they feed alone. Yet they sometimes gather together in large ‘schools’, where hundreds all swim together.

Picture Credit : Google

Angel sharks have very large pectoral fins, like an angel’s wings. They spend much of their lives on the ocean floor, waiting for fish or shellfish to come along so they can snap them up.

Is it true? Angel sharks look like monks.

Yes. Angel sharks are also called monkfish because their heads are the same shape as a monk’s hood.

What is a ‘pig fish’?

The Port Jackson shark is known as the ‘pig fish’, or ‘bulldog shark’. It has a blunt head and a squashed nose with very large nostrils for finding sea urchins and shellfish.

Which shark uses a disguise?

The wobbegong shark is a master of disguise. The colouring and markings of its flattened body help it blend into its surroundings on the seabed. It also has a ‘beard’ of skin around its mouth which looks just like seaweed to unsuspecting prey.

Amazing! If a swell shark is attacked by a predator, it gulps down as much sea water as it can and, swells up like a balloon. It then jams itself into a crack in a rock where its enemy can’t reach it.

Picture Credit : Google

Tiger sharks will eat anything. They are not put off by a crunchy turtle shell, or a stinging jellyfish, or even a poisonous snake. They will happily munch dead animals that have been washed out to sea, old boots, papers, tin cans, plastic bags — and even people!

Amazing! Sometimes when a shark feeds, others join in. They get excited at the blood and movement around them, and seem to go crazy, biting, twisting and turning wildly in a ‘feeding frenzy’.

How many teeth do sharks have?

Sharks are born with jaws full of teeth, neatly arranged in rows. They grow teeth all their lives. When front ones wear out or are lost, they’re replaced by new teeth behind.

Is it true? A shark’s teeth last for months.

No. Once a rear tooth has moved to the front row, it may drop out, snap off or be worn away in as little as two weeks.

Do all sharks have the same teeth?

The shape and size depend on a shark’s food. For example, the great white has slicing teeth for tearing off chunks of seal or dolphin. The Port Jackson has sharp front teeth to hold shellfish, and blunt back teeth to crush them.

The biggest fish is also one of the most harmless, the whale shark. It measures 1.5 metres long and weighs about 1.3 tonnes. It swims slowly through the sea with its mouth open wide, filtering millions of tiny creatures from the water.

Is it true? You could hitch a ride on a whale shark.

Yes. These gentle giants have been known to allow scuba divers to hang on to their fins and ride with them.

Amazing! Little is known about the megamouth. But we do know that it has luminous organs that give off a glow around its lips. Scientists think this may be to tempt tiny creatures into its mouth.

Which shark appears to sunbathe?

Basking sharks spend much of their time wallowing at the ocean’s surface, especially when it’s sunny — probably because there’s more food there on sunny days, not because they want a suntan!

What has a huge mouth?

The megamouth shark lives in deep, dark seas. Like the whale shark, it swims with its enormous mouth wide open, filtering water for food. It is very rare and only a few have ever been seen.

Picture Credit : Google

Sharks have the five senses of sight, smell, taste, hearing and touch. They also have one more. Sensitive cells on their snouts allow them to pick up tiny electrical signals from other animals.

How do sharks know when an animal is struggling nearby?

Sharks can tell that there are animals in their area, even when there is no blood to smell. A sensitive ‘lateral line’ along their bodies allows them to feel ripples in the water from any struggling animal or person.

Do sharks have good eyesight?

Sight is important in the final moments of a shark’s hunt. But sharks depend much more on their sense of smell. Sharks get very excited at the smell of blood. They can smell a drop of blood, diluted millions of times, nearly a kilometre away.

Is it true? Sharks nudge their food before they take a bite.

Yes. They sometimes nudge an object or animal with their snout before they decide whether to eat it or not! Perhaps they can ‘taste’ it with special cells in their skin.

Amazing! Most fish have scaly skin, but a shark’s tough skin and scales are very different. They are sharp points called denticles which are like teeth. Shark skin was once used for smoothing down wood, instead of sandpaper.

Picture Credit : Google