🦈 All About Sharks
Sharks have been swimming in our oceans for over 450 million years — they were here long before the dinosaurs. There are over 500 species, from the bus-sized whale shark to sharks small enough to fit in your hand. Despite their fearsome reputation, sharks are vital to healthy oceans and far more threatened by humans than humans are by them.
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Great White Shark
- Can detect one drop of blood in 100 litres of water
- Has 300 teeth arranged in multiple rows
- Existed for over 11 million years — much older than humans
- Can swim at 56 km/h in short bursts
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Whale Shark
- The largest fish in the world — up to 12 metres long
- Despite its size, it eats only tiny plankton
- Swims with its mouth open, filtering 6,000 litres of water per hour
- Can live for over 100 years
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Incredible Senses
- Can detect electrical fields produced by other animals using special organs called ampullae of Lorenzini
- Sense of smell so powerful they can smell blood 400 metres away
- Can sense movement in the water through their lateral line
- Some species can see in very low light, like deep sea sharks
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Shark Teeth
- Sharks have no bones — their skeleton is made entirely of cartilage
- Most sharks go through 30,000 teeth in their lifetime
- Teeth can fall out and be replaced in as little as 8 days
- Fossilised shark teeth are one of the most commonly found fossils worldwide
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Amazing Shark Behaviour
- Hammerhead sharks use their wide heads to pin prey to the seabed
- Some sharks must keep swimming to breathe — they force water over their gills
- Nurse sharks can breathe while completely still on the ocean floor
- Some sharks travel thousands of kilometres — great whites have crossed the entire Atlantic
⚠️
Sharks Need Protection
- Humans kill approximately 100 million sharks per year
- Sharks kill an average of only 5–10 humans per year worldwide
- Sharks are apex predators — removing them collapses entire ocean ecosystems
- Over one third of shark species are now threatened with extinction
✨ Amazing Shark Facts
🦈 Shark skin feels like sandpaper — it is covered in tiny tooth-like scales called denticles that reduce drag as they swim.
🏦 The Greenland shark is the longest-lived vertebrate on Earth — one was estimated to be 512 years old.
👀 Some sharks glow in the dark! Kitefin sharks produce bioluminescent light — they are the largest known glowing vertebrate.
🐺 Baby sharks are called pups. Some species give birth to live young; others lay eggs in cases nicknamed ‘mermaid’s purses’.
🎯 The bull shark can survive in both salt water AND fresh water — they have been found hundreds of kilometres up rivers.
🧬 Fossilised shark teeth are so common on beaches that people find them regularly — because sharks shed thousands of teeth throughout their lives.
🤔 Shark Quiz
Click each answer to check it instantly!
Question 1 of 6
What is the largest fish in the world?
- Great White Shark
- Hammerhead Shark
- Whale Shark
- Basking Shark
Question 2 of 6
What are a shark's ampullae of Lorenzini?
- Organs that detect electrical fields produced by other animals
- A type of scale covering the shark's body
- Special teeth used for gripping prey
- The shark's hearing organs on either side of its head
Question 3 of 6
Approximately how many teeth does a shark use in its lifetime?
- About 30,000
- About 3,000
- About 300
- About 300,000
Question 4 of 6
What is a shark's skeleton made from?
- A mixture of bone and cartilage
- The same bone as other fish
- Ivory, similar to elephant tusks
- Entirely cartilage — sharks have no bones at all
Question 5 of 6
Why are sharks so important to ocean ecosystems?
- As apex predators, removing sharks causes the entire food web to collapse
- They clean the seabed by eating dead matter on the ocean floor
- They eat so much that they keep plankton populations balanced
- They produce oxygen that other sea creatures need to breathe
Question 6 of 6
How many humans do sharks kill per year on average?
- About 100
- About 500
- About 50
- About 5 to 10
📚 Key Words
cartilage
The tough, flexible tissue that makes up a shark's entire skeleton instead of bone.
apex predator
An animal at the very top of the food chain with no natural predators.
ampullae of Lorenzini
Special organs in a shark's snout that can detect tiny electrical fields produced by other animals.
lateral line
A sensory system running along a fish's side that detects vibrations and movement in the water.
plankton
Microscopic organisms that drift in water. Despite its size, the whale shark eats only plankton.
cartilaginous fish
Fish whose skeletons are made from cartilage rather than bone. Sharks, rays and skates are all cartilaginous fish.
extinction
When an entire species no longer exists anywhere on Earth. Over a third of shark species are now threatened.
ecosystem
All the living things in a particular area and how they interact with each other and their environment.
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