Interesting Facts >> Animals >> Sharks

21 Shark Facts - Learn About the World's Sharks

by Brandon Cornett

Shark. They very word sends a shiver up the spine of many people. We have been taught by pop culture that sharks are man-eating monsters to be feared and/or hunted.

But this is simply not the case. In reality, sharks are fascinating animals that have existed on this planet long before mankind. After reading these interesting facts about sharks, we hope you will see them in a whole new light.

21 Interesting Facts

1. According to our current system of scientific classification (known as "taxonomy"), there are more than 400 species of sharks in the world.
2. It's a fact that sharks have been around for more than 400 million years, long before humans. Modern sharks are very similar to their ancient ancestors, in both form and function.
3. Megalodon was a gigantic prehistoric shark that made the great white look like a rainbow trout. Fossilized remains suggest that this shark may have lived as far back as 18 million years. Scientists believe it became extinct 1 - 2 million years ago. Based on fossil evidence, it could have grown to lengths of 50 feet or more. That's one big shark!
4. Sharks exist in a wide variety of water temperatures and depths. Some species prefer warm, tropical waters while others thrive in cold, arctic waters. Some sharks can even survive in freshwater lakes.
5. Some sharks have the ability to give birth without ever having mated. In 2001, at the Nebraska Zoo, a female bonnethead shark (a hammerhead subspecies) gave birth to a healthy baby without ever being paired with a male shark. Today, researchers believe that many species have this unique ability.
6. Many types of sharks are threatened with future extinction. While they are regarded as apex predators (at the top of their food chain), there is one predator who still threatens them -- and that is mankind. Each year, thousands of sharks become victims of commercial fishing nets, while others are hunted for their fins.
7. The worst shark attack ever occurred during World War II, back in July of 1945. A Japanese submarine fired two torpedoes into the USS Indianapolis. The U.S. warship was destroyed, and 900 sailors ended up floating in the waters of the Pacific Ocean. Four days later, when a rescue vessel came, only 321 were still alive. The remaining 579 sailors had died, most of them eaten (or partially eaten) by sharks.
8. All sharks have a preferred food source, but most will eat anything. Stomach content examinations of captured sharks have revealed everything from car tires to cows.
9. It's a fact that sharks have a powerful sense of smell. They can detect minor traces of blood in the water, as little as one part per million. This is why groups of sharks often arrive on the scene of a large kill -- they are attracted by the blood.
10. In addition to their senses of sight, smell and hearing, sharks have something known as electroreception. This gives them the ability to detect electrical impulses put off by other animals, which helps them "zero in" on their prey. Aside from sharks and rays, only a few other animal species have this ability.
11. Sharks have a nearly endless supply of teeth. When old teeth are damaged and lost, new teeth are always ready to replace them. A single shark can shed thousands of teeth in its lifetime.
12. Shark attacks resulting in death are very rare, when you consider the sheer volume of ocean / beach activity that takes place around the world. Statistically speaking, you are more likely to die from falling out of bed than by a shark attack.
13. The appropriately named goblin shark (Mitsukurina owstoni) is one of the most elusive sharks of all. This deep-sea creature lives in water depths ranging between 800 and 3,000 feet, and it hardly ever comes near the surface. As you might imagine, the goblin shark is rarely captured on film.
14. Goblin sharks have a very large geographic range. They have been found in waters ranging from South African to the Gulf of Mexico. They are most commonly encountered off the coast of Japan, where the often get caught up in fishing lines.
15. Great white sharks (Carcharodon carchariasare) very well adapted for hunting and killing. When a great white attacks, its eyes will roll back into its head to protect them from injury.
16. The great white shark has a tremendous depth range. They can be found on the surface of the ocean (where they often hunt seals, birds and porpoises) and as deep as 4,000 feet.
17. On average, great white sharks can reach lengths of 15 - 20 feet and can weigh around 2,000 pounds. The largest great white shark ever recorded was nearly 24 feet in length and weighed over 5,000 pounds. There have been claims of even larger specimens, but most of these claims are unverified.
18. The shortfin mako shark (Isurus oxyrinchus) is one of the fastest sharks in the world, if not the absolute fastest. These sharks have been clocked at speeds over 40 miles per hour. They can also "leap" more than 20 feet out of the water when attacking prey in their typical upward ambush fashion.
19. The whale shark is easily the world's largest fish, dwarfing all other shark species. For obvious reasons, nobody has ever weighed one of these animals, but scientists estimate that they could weight more than 10 tons (20,000). They can grow to 50 feet long.
20. The biggest sharks tend to eat the smallest prey. The three largest species -- whale, basking and megamouth sharks -- are all filter feeders, subsisting on plankton, krill and small fish.
21. The lanternshark is named for its ability to illuminate its body. This trait is called bioluminescence. The dwarf lanternshark (Etmopterus perryi) is the smallest of all sharks, rarely growing longer than 8 inches in length.

I had two goals when I created this fact sheet. Goal number one, obviously, was to be factual. Each of these facts were carefully researched and written to be as accurate as possible.

My second goal with this list of shark facts was to make you say "Wow!" I believe that the secret to shark conservation is respect. After reading the 21 facts listed above, you'll have a newfound respect for sharks. And when you respect something, you are more inclined to protect it.

References: Much of this fact sheet was compiled from widely available information on dragonfly species. I also referred to the shark section of the Discovery website quite a bit, which is certainly worth a visit. There are several inline citations (hyperlinks) within the article itself.

About the Author
This fact sheet was provided by Brandon Cornett. Brandon is the creator of 21Facts.com. He is also a freelance writer and the author of many articles that can be found all over the Internet.