Often misunderstood as terrifying monsters, sharks are being hunted close to extinction yet they’re vital to the health of our oceans. Here’s 113 interesting facts about sharks to help you appreciate them better…
Sharks have survived 5 mass extinctions including the one that killed the dinosaurs.
Today there are more than 450 known species of sharks living in our oceans.
Sadly, nearly one in four of these species are currently threatened with extinction due to human activities like overfishing and shark finning.
Sharks boost local economies through ecotourism. Over the last several decades, public fascination with sharks has developed into a thriving ecotourism industry in places such as the Bahamas, South Africa, and the Galápagos Islands.
Humans kill up to 100 million sharks per year.
Sharks are killed to supply the demand for their fins, which are made into soup and eaten as a status symbol.
You’ve probably eaten shark if you’ve been traveling in Europe and are a fan of fish and chips. Spiny dogfish sharks are popular in the international market.
Shark anatomy has inspired smart design such as watercraft, cars, and water turbines.
Some researchers are now trying to make artificial shark skin that would reduce friction drag and prevent the accumulation of algae and barnacles in the water and even prevent bacterial growth when applied to hospital surfaces.
The megamouth shark was only discovered in 1976, and fewer than 100 of these rare sharks have ever been seen. It grows to an average of 16 feet and siphons plankton out of the water to feed.
Even more recently was the discovery of the pocket shark, a 5-inch shark found in the Gulf of Mexico. It glows under the water to attract prey.
Hammerhead sharks’ eyes are on the sides of their heads, so they have nearly a 360-degree sightline. Their panoramic view of the undersea world is inhibited by two blind spots, one in front of the snout and the other directly behind the head.
Sharks’ skeletons are made of pure cartilage and muscle. Since it’s half the density of bone, this makes the shark lighter and more flexible.
Shark teeth are resistant to cavities. They’re covered in fluoride, an enamel known as fluorapatite. This material is resistant to acid created by bacteria.
Sharks also go through several sets of teeth in their lifetimes, shedding and growing new teeth periodically.
Not all sharks have the same type of teeth, mako sharks have very pointed teeth; while white sharks have triangular, serrated teeth – all leaving a unique mark on their prey. The average shark has 40-45 teeth in up to 7 rows, which they tend to lose regularly and can go through an astonishing 30,000 teeth in their lifetime!
Because sharks are constantly losing and replacing teeth, experts say there are trillions of teeth sprinkled on the ocean floor.
Sharks can freely move both their upper and lower jaws.
Sharks exhibit great diversity in their reproductive modes. There are oviparous (egg-laying) species and viviparous (live-bearing) species.
Female sharks can be impregnated by multiple partners at once.
Through a process that has been observed in many animals, sharks can also clone themselves through parthenogenesis, a type of external fertilization. This has been seen in female sharks being kept in captivity.
Sharks are so tough, their embryos are known to attack one another.
Partly because they need to carry shark babies, females tend to be larger in most shark species.
Humans are a far greater danger to sharks than they are to us. There are fewer than 200 shark-human interactions globally every single year.
Great White shark
Sharks have a variety of feeding habits. Many species of sharks are filter feeders that eat small marine life, such as clams, and many are bottom feeders who use suction to gather food. Only some species of sharks are hunters that attack seals, dolphins, and other large sea creatures.
Sharks have the same five senses as human beings plus one more. Sharks have an organ in their snouts, ampullae of Lorenzini that allows them to sense electrical fields in the water emitted by other fish and marine life.
Sharks don’t sleep like humans. Since some species have to continue swimming in order to breathe, instead of falling into a deep sleep, sharks remain semi-conscious.
Most sharks have to keep swimming to pump water over their gills. However some bottom dwelling sharks such as angel sharks and nurse sharks have an extra respiratory organ called ‘sharks spiracle’ which supplies oxygen directly to the sharks eyes and brain – so they are able to breathe while at rest on the seafloor.
Scientists have been using a new method of determining shark age by using a radiocarbon timestamp found in the vertebrae of sharks left over from nuclear bomb testing in the 1950s and 1960s.
While sharks live in all of the world’s oceans, a few species are also known to inhabit freshwater lakes and rivers.
Despite what you may have seen in Walt Disney’s “Finding Nemo,” sharks definitely can’t talk, even to other fish. Sharks have no vocal cords; therefore, they make no vocal sounds whatsoever. Instead, they communicate through body language.
Great White shark
Large sharks have a bite twice as powerful as that of a lion, and can exert a pressure of up to 40,000 pounds per square inch.
Sharks can only swim forward because their fins are stiff and cannot be controlled by muscles.
They have an amazing sense of hearing. They can hear prey up to 3000 feet away.
Sharks have the thickest skin of any animal species – some sharks even have skin that is 6 inches thick!
Here’s some surprising facts about basking sharks…
Basking sharks are enormous, though they aren’t exactly the huge, toothy creatures you’d imagine them to be. In fact, while they do have plenty of teeth, they don’t actually use them to eat, if at all. They have huge, gaping mouths, which they use to scoop up and swallow prey. They are known as filter feeders.
Believe it or not, despite being some of the biggest sharks you’ll find in the deep, they are generally safe to dive and swim around. This means that – while they can look pretty mean – they are unlikely to pull a ‘Jaws’ on you any time soon! They are similar to whale sharks in this respect and are therefore very popular marine life to swim around and dive with.
The fins of the basking shark are truly massive. They are said to be able to grow up to 2m each. This likely helps to go towards their incredible weight – the biggest basking sharks can grow up to 6,000kg, generally!
You’ll likely find basking sharks in some of the milder seas around the world, though they do appreciate colder waters. They are sometimes referred to as sub-polar creatures.
Sadly, basking sharks have, over the years, been sought for various resources. They have been widely hunted by humans over the years not only for food, but also for their oil, and their huge fins.
On the whole, basking sharks are seen as the gentle giants of the shark world. This is because they filter their prey and tend to swallow up smaller creatures as they go. As such, they are not known to hunt down and seize upon their prey like other sharks and marine life. This also goes to help them gain a reputation for being some of the friendliest sharks on the planet.
Sadly, basking sharks are endangered. As a result of their hunting – as stated above – they are seen as vulnerable. They are even protected in the US, as well as over on the Gulf Coast of the US. The more we understand and appreciate about these wonderful creatures, the more action we can – and should – take to protect them.
The basking shark has a truly enormous liver! Believe it or not, the general basking shark liver makes up around 25% of its total body weight. However, it has a rather small brain to body ratio – though that doesn’t make these animals stupid!
Basking sharks are still something of a mystery to a large extent. While we know how they feed – again, to some extent – the exact reasons and motives behind their behaviours, as well as the way they mate, are still being studied.
It’s thought that the basking shark gets its name because they tend to bask in the sun a lot while feeding. In fact, researchers and experts believe that they tend to gravitate towards warmer climes all year round, evidentially so thanks to the fact that they don’t surface or even go near the top of the water in the winter.
Despite the fact that basking sharks are amazingly docile, they have also helped to build towards a number of urban legends over the years. This is partly thanks to the fact that they are so massive, as well as the fact that they do still look rather fearsome! It’s thought to have helped given weight to the legend of the Stronsay Beast, for example. However – we’re not sure you’ll find a Basking Shark in Loch Ness to explain the local Nessie legends!
How does something so massive stay buoyant? The basking shark’s body is rich in squalene, which helps it to float around.
Lets move on to the largest of all predatory sharks in the ocean today, the Great White Shark…
Great whites are torpedo-shaped with powerful tails that can propel them through the water at up to 15 miles per hour.
Found in cool, coastal waters around the world, great whites are the largest predatory fish on Earth.
Great whites are found mostly along the coasts of Australia, South Africa, California, and the north-eastern United States.
They grow to an average of 15 feet in length, though specimens exceeding 20 feet and weighing up to 5,000 pounds have been recorded.
The only two fishes that grow larger than Great Whites are the whale shark and the basking shark, both filter feeders that eat plankton.
While the shark in Jaws was inspired by a great white shark in New Jersey, the legendary fish is far less fearsome in reality.
They have slate-grey upper bodies to blend in with the rocky coastal seafloor, but they get their name from their white underbellies.
Reaching lengths of up to 20 feet (6 m) and weights of several tons, the great white’s body is perfectly adapted to a life of predation.
Highly adapted predators, their mouths are lined with up to 300 serrated, triangular teeth arranged in several rows.
They have an exceptional sense of smell to detect prey.
Sharks have a tongue made of cartilage called a basihyal. They use it to sample prey, to see if it’s a good idea to eat it or not.
Great Whites don’t chew their food. They rip their prey into mouth-sized pieces which are swallowed whole.
Their prey includes other sharks, crustaceans, molluscs, and sea birds, sea lions, seals, and small toothed whales like orcas.
Great white sharks can detect one drop of blood in 25 gallons (100 l) or water and they can sense even a little blood up to 3 miles (5 km) away.
They use their acute sense of smell to detect blood using an organ called the olfactory bulb.
Great whites are known to take very deep dives, probably to feed on slow-moving fishes and squids in the cold waters of the deep sea.
They have a specialized blood vessel structure, called a counter-current exchanger that allows them to maintain a body temperature that is higher than the surrounding water.
Of the 100-plus annual shark attacks worldwide, a third to a half is attributed to great white sharks. Most of these, however, are not fatal.
Research finds that great whites, which are naturally curious, often “sample bite” then release their human target. It indicates that humans are not actually on the great white’s menu.
Fatal attacks, experts say, are typically cases of mistaken identity: Swimmers and surfers can look a lot like their favourite prey, seals when seen from below.
Great white sharks are very curious and will often poke their heads out of the water or follow boats just to see what’s happening, a behaviour called spyhopping.
Because of this natural curiosity, great whites are known to approach boats to look at people. This is not an aggressive behaviour, it’s just the shark’s way of seeing what you are.
People, on the other hand, capture too many great whites through targeted fisheries or accidentally in other fisheries.
Scientists generally consider great whites to be vulnerable to extinction.
Great whites mate via internal fertilization and give live birth to a small number of large young (over three feet/one meter).
While in their mother’s womb, young great whites swallow their teeth. They may do this to reutilize calcium and other minerals.
Though they give live birth, great whites don’t connect to their young through a placenta. Instead, during the gestation period, the mother provides her young with unfertilized eggs that they actively eat for nourishment.
After they are born, young great whites are already natural predators, and they eat coastal fishes.
A baby shark is called a pup. When the pup is born, it is 4 to 5 feet (1.2 to 2.5 m) long and completely able to take care of itself.
According to a 2014 study, the lifespan of great white sharks is estimated to be as long as 70 years or more, well above previous estimates.
There is no reliable population data for the great white shark, but scientists agree that their number is decreasing precipitously.
Great white sharks are known to be highly migratory, with individuals making long migrations every year.
As large and powerful predators, great white sharks play an important role at the top of the marine food chain.
Stationed on the South African coast, Shark Spotters have added a new tool to their trade, employing drones to get a closer look at what lies below the water at Cape Town’s popular beaches.
Shark fins are unique and South African scientists are using them to identify individual sharks without using tags.
In 1991, the fishing and exploitation of great white sharks became illegal in South Africa, the first country to protect great white sharks.
Here’s 15 scary yet interesting facts about Tiger Sharks…
Tiger Sharks can weigh 1,300 lb and grow to 15 ft long.
They’re the fourth largest shark behind the Whale Shark, Basking Shark, and Great White.
Tiger Sharks are the ocean’s bin men because they love to gobble up pure garbage.
They’ll even eat tyres and leather jackets for sustenance.
Their distant cousins are the Sand Tiger Sharks, but they’re more closely related to Great Whites.
A baby Tiger Shark has spots not stripes.
As the babies reach maturity their spots begin to blend together and form their iconic stripes.
Tiger Sharks love nothing more than relaxing in 22 C water.
Notched teeth allow them to both hold onto prey and rip it to bits once they’ve killed it.
They’re the only shark known to hunt sea turtles on a regular basis.
Their gestation period is 14-16 months and results in average litter sizes of 30 or more.
One female has been seen to birth 80 pups at the same time.
A typical newborn pup weighs 6-13 lb.
Whale sharks are majestic monsters of the deep which are always breaking records – here’s a few interesting facts which may surprise you:
Their names can be confusing – they have nothing to do with whales, but they are sharks. However, they get their whale name from their sheer size – they are absolutely massive!
Let’s talk figures, if we’re considering size. A whale shark could get to be as big as 12m in length, or 40 feet! They can weigh up to 20 tons, on the whole. That makes them likely to go shoulder to shoulder with some of the bulkiest traffic on our roads right now!
The whale shark’s mouth is big enough to swallow some people whole, They have mouths which extend up to five feet, or a metre and a half wide.
Whale sharks are carnivores; however, they eat much differently compared to other sharks and meat-hunting fish. They have more than 3,000 teeth, but don’t actually use them to tear and eat flesh. They simply swallow and filter – highly efficient to swim along like a big fish-shaped scoop!
Whale sharks are amazingly patient, especially when it comes to gobbling up prey. They will often skulk around for hours at a time for eggs to be laid, before swimming up and gulping them down. They can be very sneaky!
The whale shark is likely to gobble down a variety of different critters, with squid and smaller fish likely to be high up on their menu, on the whole.
As you can imagine, whale sharks are the biggest fish on the planet, not just the biggest sharks. That’s an impressive record, given how many different beasties there are out there.
Don’t worry – despite their massive nature, they are fairly friendly around humans, and are unlikely to pose threats to scuba divers. It’s perfectly possible and safe to swim with and around whale sharks, though safety is, as always, recommended.
Whale sharks have the ability to grow to be a ripe old age – they can live to survive to be over 100 years old in the wild, though unfortunately, 90% of all whale sharks are unlikely to survive their childhoods, according to official conservation sources.
In fact, there are massive whale shark conservation efforts always going on. That’s as a result of accidental fishing causing them to be caught and trapped. However, aspects of climate change, pollution and plastic damage, too, are likely to be steadily destroying their habitats.
It’s thought that the whale shark population across the globe has already shrunk by up to 63% in the past 75 years. Therefore, efforts to try and protect these wonderful creatures have been ramping up hugely over the past few decades.
It’s likely that you will find whale sharks in some of the warmer waters of the world, however, it is not unheard of to find them off the coast of the US. They’ve been seen in the Atlantic, but you’ll normally spot them while traversing the Pacific.
The whale shark is likely to breathe in 6,000 litres of water each and every hour. It has some really powerful gills to say the very least!
However, as a result of their huge size, it’s unlikely you will ever see a whale shark moving too fast. The fastest they can swim is at a trundle of around three miles per hour. However, as they are so massive, they’re unlikely to come under threat of anything natural below the waves.
Whale sharks have unique, interesting heads compared to other sharks. That’s because their mouths position towards the front of their heads, not underneath. This, of course, helps them to uniquely scoop and filter their prey, as you can imagine.
Whale sharks actually lack the power to chew, meaning that despite its many teeth, they will only ever act as a filter mechanism.
Do you know any interesting or fun facts about sharks? Share them in the comments below!