5 amazing facts about whale sharks
Date posted: 28 August 2020
By Rachel Horne
Ahead of International Whale Shark Day (August 30) we dive in to 5 amazing facts about these gentle giants.
There is so much that we still don’t know about whale sharks. We don’t know how many there are, we don’t know where they mate or give birth, and we don’t even know where they go for most of the year! We do know that they are a vital indicator of healthy oceans.
They migrate thousands of miles to feed on plankton, which takes a long time considering they can only swim 3 miles an hour.
Part of the shark family, whale sharks get their name because they share many characteristics with whales. Firstly, they are enormous. They are also filter feeders, which means that they separate food from water using their inner filtration system rather than hunting down prey.
We may not know a lot about this enormous shark, but what we do know is pretty impressive.
Read on for 5 of the most amazing facts that we know about whale sharks!
1. They have 3000 teeth
That’s right, whale sharks have a whopping 3000 teeth! Luckily for us, they are not predatory. People are so rarely harmed by them that they are fondly known as gentle giants. Unfortunately, this can stop people respecting their boundaries. Divers often touch whale sharks, even grabbing on their fins to ‘hitch a lift’.
They only gather in shallow waters for brief periods, and recent research has shown that this is to rest and recover from time spent in deep cold water. With this in mind, interfering with their resting time can have more serious consequences than many divers realise.
2. They are the biggest fish in the world
Not only are whale sharks the biggest of all the sharks, they are also they biggest fish in the whole world. They weigh an average of 11 tonnes, that’s 11 times more than a great white shark! Unlike great white sharks, they don’t have much taste for the flesh. These gentle filter feeders live mostly on plankton. They also eat fish eggs, shrimp and small fish when they are available.
The whale sharks that we see gathering in shallow waters are usually young males, and are much smaller than the fully grown adults. We still don’t know just how big they can get in the deep hidden corners of the ocean.
3. They live longer than humans
If they aren’t killed by people, whale sharks can commonly live for up to 180 years. If you think 180 years is long, you won’t believe how long the Greenland shark can live for. The most mysterious of all the sharks in the sea, the Greenland shark is thought to live for 400 years.
Unfortunately, many whale sharks end up getting hunted for their oil which is used to waterproof wooden boats and as an additive to cosmetics. They are also frequently killed in boat collisions or accidentally caught by fishermen as bycatch.
They also get entangled in ‘ghost fishing nets’ that drift for decades through the sea after becoming detached from fishing boats. It’s no surprise that less than 1 in 10 whale sharks survive into adulthood.
4. Their eggs hatch inside of them
For a long time, scientists debated about whether whale sharks laid eggs or gave birth to live young. Young male whale sharks are regularly sighted at certain hotspots, but female and older whale sharks are still extremely elusive.
It has now been discovered that whale sharks give birth to live young, which hatch just before they are released into the water. One female whale shark was found to be pregnant with 300 babies. This may seem like a lot of pups, but they don’t reach sexual maturity until they are 30 years old. That’s a very long time in which they could be killed or hunted, before they can contribute to the future of the species.
At birth they are around 50 cm long and are frequently eaten by other sharks and predatory fish.
5. They have a unique ‘fingerprint’
Just like humans, whale sharks each have a ‘fingerprint’ that they can be identified from. Each individual has a unique pattern of spots and stripes on their skin. By photographing the patterns on their fins, we can identify individuals and start to collect data on how many whale sharks there might be.
Nobody knows how many individual whale sharks exist in the world. The creatures of the ocean continue to amaze people every day, as new species and behaviour patterns are constantly emerging with new research.
We have played an important part in this research. We’re helping to provide key research about whale sharks by working with the Whale Shark Research Programme since 2011, helping record sightings to better understand their behaviour.
How to help whale sharks
Although the future of ocean life is under threat, there is some good news when it comes to whale sharks. It has been consistently shown that preserving their habitats and protecting them from harm is much more profitable than hunting them. Life is priceless, of course. But in a world where money talks, it’s good to know that small communities can make much more money through whale shark tourism than from hunting the sharks.
If you would like to help protect whale sharks, here are some things that you can do:
• Share this article to help raise awareness about these amazing creatures.
• Support our work by donating money or time to help us achieve our vision of seas which are full of life, where nature flourishes and people thrive.
• Join an expedition to help monitor and protect the whale shark hotspot in the Maldives. You can also support them by participating in other whale shark tourism, but make sure you book a tour that respects the need of the sharks to rest.
• If you buy fish, make sure it has been sustainably caught. You can use our Good Fish Guide to help you with this.
• Reduce your use of single-use plastic , which often ends up in the sea and can be accidentally ingested by sharks and other fish. You can check out our Living Without Single-Use Plastic Booklet for advice and inspiration.