Sharks have been around for a very long time, over hundreds of millions of years in fact! And surprisingly there are still missing facts about sharks and information about this species that we do not know!
While many of us may be familiar with some shark species, there are over 400 of them in total. Ranging from the tiny 8-inch Dwarf kind right up to the 60-foot long Whale shark.
Sharks are the apex predators at the top of their marine food chains, and they are vital within the ocean’s ecosystems to help regulate the populations of species below them. Recent research shows that massive depletion of the species has cascading effects throughout our ocean’s ecosystem.
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Shark Facts & Popular Shark Questions
To help you learn more about this beloved species, some of the most endangered sharks in the world and just brush up on your shark info, here are 25 shark facts and most popular Shark related questions and answers!
1. What is a Shark?
First things first, what is a shark exactly? It is a long-bodied marine fish with a cartilaginous skeleton. They have a prominent dorsal fin and toothlike scales.
Most are predatory creatures, although the largest of its kind actually feeds on plankton. They range in sizes from very small, to the largest fish in the sea.
2. Are Sharks Fish?
One of the most popular questions around. Are they fish? This may seem like an easy question but it does tend to catch a lot of people out. So what is the answer?
Is a Shark a Fish? Yes, they are fish, not mammals.
They belong to a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven-gill slits on the sides of the head, and pectoral fins.
3. Where Do Sharks Live?
Sharks can be found in all five of Earth’s oceans: the Atlantic, Indian, Pacific, Arctic, and Southern. Some can also be found in freshwater lakes and rivers. As an example, the Bull species has been known to travel great distances up the Amazon River.
Unlike most other animals, they are not territorial by nature. This means that they tend to change their habitat often. One of the biggest factors when determining where they will migrate to next is the water temperature.
They are sometimes classified by the surface temperature of the water they inhabit. Another of the interesting shark facts is that there are three major classifications which are Temperature, Polar and Tropical.
Tropical
Tropical sharks, such as the Hammerhead and the Nurse shark, both inhabit ocean regions near to the equator where the waters are warmer.
Polar
Polar sharks live near the polar ice caps and have adapted to survive in the frigid waters which are just above freezing point.
Some examples of polar sharks include the Greenland Sleeper and the Black Dogfish.
Temperature
Temperature sharks inhabit the areas between the polar and tropical regions. The larger temperature sharks, such as the Great White and the large Basking species will venture out of the temperate oceans and migrate to tropical waters.
The smaller temperature sharks are unable to handle such drastic changes in water and therefore stay within regions where the temperature is more comfortable for them.
4. How Long Do Sharks Live?
Another popular question is, how long do sharks live? While the answer is unclear, it has been estimated that the whale shark, which is the largest of the species, can live up to 100–150 years old!
Many of the smaller species are known to live to at least 20 – 30 years, but this fact still remains unclear. Some scientists believe to have had found Greenland sharks around 400 years old!
5. How Fast Can Sharks Swim?
I am sure that I don’t need to point out that most are able to outswim you! We all know that they are pretty fast, but exactly how fast can they swim?
Well, the Shortfin Mako takes the medal! The Shortfin Mako is the fastest species and can swim up to an amazing 56mph, that’s over 100kph! Pretty impressive!
6. Which is the Smallest Shark in the World?
They are apex predators, but they range in a variety of shapes and sizes. Already listed within our 10 smallest animals found in the ocean, the smallest in the world is the Dwarf Lantern shark.
This tiny species is only 15 cm long, that’s 6 inches! It could easily fit into the palm of your hand!
7. What is the Biggest Shark in the World?
The Shortfin Mako takes the gold when it comes to speed, but what is the biggest in the world?
The biggest in the world and the gold medal goes to the Whale Shark and so it owns that title!
With the name to suit, they can grow to a staggering 18 meters (60 feet) in length.
Love Whale Sharks? Adopt a Whale Shark today!
Did You Know? Sharks predate the dinosaurs by over 200 million years. The largest known species, C. megalodon, might have reached a maximum length of 67 feet.
8. Can Sharks Swim Backwards?
Their pectoral fins are not able to bend upwards like that of a fish. This limits its swimming ability to forward motion only, meaning that they cannot swim backward or stop suddenly. 
If it needs to move backward, it uses gravity to sink backward rather than swim. However, there are a few species, which include the epaulette shark, which is known to “walk” backward.
9. Will They Drown if they Stop Swimming?
The fact that they must keep moving in order to survive was once widely thought to be true, but it isn’t. So will they drown if they stop swimming?
No. Although they obtain oxygen for breathing from the water that flows over their gills, many have adapted to doing this while they are still.
Most can rest on the bottom and pump water over their gills. The endangered Australian grey Nurse Sharks can hang out almost stationary in the water for ages. They are often seen resting in groups.
10. What Do Sharks Eat?
They are carnivorous and eat fish (including other sharks), seals, mollusks, crustaceans, and other marine mammals. Other types, such as the whale and the basking species, feed on tiny plankton or krill.
They have a very acute sense of smell which also allows them to be able to detect blood in the water from many miles away. Are sharks dangerous? Despite their fearsome reputation as ruthless predators, they are in fact much more likely to be killed by humans than the other way around.
11. How Much Do They Eat in a Day?
Some species tend to hunt all of the time. As an example, the Great White is always on the hunt! This type eats around 11 tons of food a year! For comparison, we humans eat on average half a ton of food each year. The Blue Sharks are known as a glutton, it will eat until it regurgitates and then goes right back to eating!
Most types will eat a meal every couple of days. If necessary, they are able to go for a few weeks without eating at all. Just like people and most other animals, they are able to store the extra energy as fat, for use later when food is limited. Did you know that the Tiger Shark has actually gained the nickname of “the garbage can of the Sea”? Find out why in our 50 facts about Tiger Sharks.
12. Do Sharks Lay Eggs?
Another very common question is do they lay eggs? And if they do, do all types lay eggs? Some are oviparous, which means they are able to lay eggs. Others are viviparous which means they give birth to live young.
Within these livebearing species, some have a placenta just like human babies, whilst others do not.
In the cases where there is no placenta, the embryos are able to get their nutrition from a yolk sac or unfertilized egg capsules within the yolk.
For the tiger shark, things are pretty competitive. The two largest embryos consume the other embryos of the litter!
13. How Do Sharks Reproduce?
All types reproduce by using internal fertilization, with the male using his “claspers” to grasp the female so he can then release sperm. The sperm is then able to fertilize the female’s oocytes. The fertilized ova are packaged in an egg case and then eggs are laid or the egg develops in the uterus.
They mature slowly and only reach a reproductive age between 12 to 15 years. This combined with the fact that many species only give birth to one or two pups at a time. Meaning that they have great difficulty recovering after their populations have declined.
Soon after they are born, the pups swim away to fend for themselves. They are born with fully-fledged sets of teeth and are therefore able to feed and live all by themselves.
14. How many Teeth Do Sharks Have?
So how many pearly whites do they have? Well, that depends on the species.
Some species only have a few dozen teeth, whilst others can have thousands! We think the biggest in the world may take the price with an outstanding amount of around 3000 teeth!
Their teeth don’t actually have roots, and because of this, they fall out after about a week. Obviously, they aren’t swimming around toothless!
But this is due to them having replacements arranged in rows, so when a tooth falls out, a new one can move in within one day in order to take the older tooth’s place. They have 5 – 15 rows of teeth in each jaw, with the majority of species having five rows.
15. Which Sharks have the Biggest Teeth?
The prehistoric Megalodon was the largest of the species to have ever lived. Their teeth could grow up to seven inches long! Relative to size, the Cookiecutter has the largest teeth.
Although this species is rather small, it uses its large teeth in its round mouth to take cookie-sized bites from the flesh of its prey, many of them being larger marine creatures such as dolphins.
16. How Strong is a Shark’s bite?
Astonishingly, the bite of one can generate up to 40,000 pounds of pressure per square inch. That’s a hell of a bite!
17. Can Sharks Smell?
Yes, they have amazing smelling abilities! So much so that their sense of smell is so powerful that some species can detect a drop of blood in an Olympic sized pool.
18. Can Sharks Detect Movement in the Water?
Yes, they can! They can detect movement in the water because they have a lateral line system along with their sides. This lining system helps different types find prey and navigate around other objects at night or when there is poor visibility within the water.
The lateral line system is made up of a network of fluid-filled canals hidden beneath the skin. The pressure waves in the ocean water around it can vibrate this liquid. This is then transmitted to jelly in the system which then transmits to its nerve endings where the message is then relayed to the brain. Pretty cool huh!?
19. How many Bones does a Shark have?
So how many bones does a shark’s skeleton have? Sharks do not have bones! Being a cartilaginous fish, their skeletons are made completely out of cartilage.
This is the same material that is found in our human nose and ears!
20. What are a Shark’s Main Predators?
These apex predators are known to be at the top of the food chain, but the sad truth is, us humans are hands-down the biggest threat and danger to sharks.
People are the ones responsible for killing millions every year. There are other animals known to eat them though, these include, killer whales, crocodiles, and even larger types of their own species.
21. Which Shark is the most common?
Out of the different types, the ocean whitetip is the most common shark. This large type is numerous in both the Atlantic and Pacific oceans.
Out of the smallest of the species, the Spiny Dogfish ranks the most common with millions found in the North Atlantic.
22. What is the most Dangerous Shark in the World?
Sharks and humans!!! Another common question that comes up is, which is the most dangerous? The great white, more commonly referred to as the “Great White,” has been reported to be involved in more attacks on humans than any other kind of its species. Although there are also a lot are harmless sharks.
This, in turn, will make it the most dangerous of it kind in the world. However, it’s important to know that there are very few fatal attacks each year. In fact, statistically, you are more likely to be killed by a cow, than you are a shark. Learn more Great White Sharks Facts here!
23. How Many Species of Shark are There in the World?
Although there is still so much that we do not know about them, however, it is estimated that there are around 440 known species in the world.
Some species are more famous than others, such as the iconic Great White featured in Jaws – for better and for worse.
Scientists believe that there any many more species yet to be discovered out there in the deep blue.
24. What is the Population of Sharks in the World?
It seems to be too difficult for experts to estimate the population numbers since there are so many different species spanning such a large geographic area. However, it is certain that overall numbers are on the decline due to the many threats they face in the wild. Experts estimate that around 100 million are killed by people every year.
Humans are their biggest threat as they continue to be eaten as seafood in many areas around the world. Both commercial and recreational fisheries are also believed to be responsible for the reduced populations of the species.
25. What is Shark Week?
It is a week-long programming block produced by the Discovery Channel and usually takes place in July or August every year. During this time, the Discovery Channel broadcast programs and documentaries about the species in over 72 countries around the world.
It gets heavily promoted by fans all over Social Media and by fans of the Discovery Channel every year. Although, in recent years, there has been some controversy about the event and how the Week has lost its values. Find everything you need to know about Shark Week here.
