50 Facts About Sharks

In our beautiful blue planet, there are nearly 71% of the surface area are covered by the Ocean, in number, it's about 140 million square miles (362 million square km), and yet our human beings only explored less than 10% of the Earth's living space... When we talk about the Ocean, we also think of one of the most mysterious and amazing creatures - Sharks.

Since when we were kids, most of us misunderstood sharks by differnet horror stories we heard from our parents, our friends, the cartoons... When we thought about sharks, we even thought they are all big aggressive man eaters. Untill one day, by some random chance, we finally get to know them a bit more ...

Can't wait to share this to you all ;-)

First of all, let's watch a video from Blue Sphere Media:

End the War on Sharks from Blue Sphere Media on Vimeo.

Here are the 50 facts that you might or might not heard about before about sharks :

  1. Sharks have been on our oceans for over 450 million years, in the late Silurian period. And the first sharks looked very very different from the modern sharks. However, even the majority of the modern sharks can be traced back to more than 100 million years ago!

  2. Sharks measuring from 0.2 meters to 18 meters long, there are at least 500 shark species (perhaps more) roaming the world's oceans today. They vary in size and shape, one the largest sharks is the majestic Whale sharek, It floats around much of the world’s tropical waters feeding on the tiny shrimp-like organism, krill. While the smallest shark are the dwarf lantern sharks which are mostly only 0.2 meters long (smaller than your hand!), and some of them even shorter.

  3. All shark skeletons are made of cartilage, so just like our human ears, it's not really hard bones, instead it's a flexible and lighter tissue which is also considered bone but gives sharks the speed underwater and the flexibility they need to be the dominant predators they are.

  4. While we learned to fear sharks, the truth is sharks should really be feared of us, humans are sharks’ most deadliest predator. As every year, we keep end up kill more than 100 million sharks. While most likely we would have a 1 in 63 chance of dying from the flu compare to a 1 in 3,700,000 chance of being killed by a shark during our lifetime.

  5. Mako shark is the fastest shark on Earth. It reaches up to 32 kilometers per hour with gusts of 72 km/h and is capable of traveling up to 55 kilometers in a single day. It also can jump, as it has been seen doing it out of the water reaching up to 9 meters height. This shark inhabits all the temperate waters of the world, with larger concentrations in the Pacific, Atlantic and Indian oceans and in the Red Sea and the Mediterranean.

  6. Swimming is the one that regulates buoyancy in many marine animals. Therefore many sharks have to swim constantly to avoid sinking. Sharks continue to swim during sleep, except during lunar eclipses. On these rare occasions, they cluster together on the sea floor and sleep in "Shark piles", a single shark piles can consist between 12 to 400 animals.

  7. Overfishing can have a dangerous effect on sharks. The whale shark, for example reached maturity at the age of 30 before they start reproducing! Unfortunately many sharks are caught at such a large scale and so often, many sharks don’t reach maturity to help repopulate their number.

  8. The basking shark is widely distributed throughout the world's oceans, in temperate and tropical waters, often swims close to the surface with its mouth widely open, filtering plankton from 6,000 litres per hour. Although a massive and powerful fish, basking sharks are harmless and are considered a gentle giant of the ocean.

  9. Sharks mature slowly, and reach reproductive age anywhere from 12 to 15 years. This, combined with the fact that many species only give birth to one or two pups at a time, means that sharks have great difficulty recovering after their populations have declined.

  10. The Megamouth shark is an exotic species discovered in 1976. It has a length of 4 – 5 meters and weighs about 800 kilograms. It's an inhabitant of the deep waters (between 150 and 1,000 meters) that likes moderate and warm temperatures. The research gave evidence that this shark is a vertical migrant during 24-hour cycles, spends days in deep water and nights in mid-depth waters.

  11. Xenacanthus is another genus of sharks that inhabited the Earth from the late Devonian to the mid-Permian period, 202 million years ago. They were some of the first freshwater sharks.

  12. Lemon Sharks were first described in 1868, a largest populations of this species inhabit regions of the Atlantic Ocean. This shark likes to inhabit coastal shallow waters. The usual depth in which they live is around 90 meters.

  13. Genetically, the land animal that the Great White shark most closely resembles is the giant panda. Their digestive tract and cerebral cortex are almost identical and the two share a common ancestor in the zebra trilobite. Around 300 million years ago, a single gene mutated into an "adorable" and "ferocious" form, and the two separate species began to evolve.

  14. Bull sharks have a fondness for freshwater. They’ve been spotted in bays, lagoons and even rivers, sometimes thousands of miles inland.

  15. The Goblin shark is a rare species of deep-sea shark discovered in the late 19th century, it also has been scientifically proven to be the ugliest living creature. It is often called a “living fossil” since its ancestry goes back to the Cretaceous period and it keeps such primitive characteristics. The sightings of goblin sharks are very rare and indicate that the species lives in waters on continental platforms and slopes, at depths of 1,300-1,370 meters.

  16. Female tiger sharks have two different uteri, and these are the key to giving birth to at least two pups. Some kinds of sharks lay eggs. Others, like the sand tiger sharks can give birth to live young called pups. A newborn can swim and eat right away.

  17. Blue sharks are among the most threatened species of sharks in the world. Trade in shark fins and overfishing have caused them to decline so rapidly that scientists worry about their future recovery.

  18. Until recently, sharks were thought to be immune to cancer. However, recent research proves that sharks too develop cancer, a variety of illnesses and deformities.

  19. The Great White Shark are notoriously ticklish around the pelvic fin, if you find the correct spot and it will roll on to its back with a look of benign ecstasy on its face.

  20. The 6 Gill Frilled Shark lives thousands of meters below the ocean surface. The first time this shark was recorded alive on film was in 2007 when a specimen was caught in Japan.

  21. Even though sharks have rows and rows of razor-sharp teeth, they don’t use their pearly whites to chew their prey. Shark teeth are strictly for snapping, grip, crush or rip, and the resulting chunks are swallowed whole.

  22. The prehistoric shark Megalodon probably grew to 60 feet (18 meters), and it’s popularized today as the largest shark ever to exist. However, there was another plated fish called the Dunkleosteus, which, though not a shark, weighed in at around 4 tons. If they’d lived during the same era, Dunkleosteus could have proved to be a deadly match for the Megaladon.

  23. The size of a shark species relates to where they hunt: Smaller sharks tend to feed near the ocean floor, and larger sharks hunt in the middle depths and near the surface, where they can more easily snatch larger prey such as seals.

  24. Blue sharks are piggy eaters. They’ll keep eating until they regurgitate, after which they go back to eating!

  25. You can’t see a shark’s ears, but that doesn’t stop it from being able to hear you from more than two football fields away. That’s because sharks only have inner ears, which they use to track the sound of their prey from lengths of more than 800 feet (244 meters).

  26. Different species of sharks have their own set of etiquette during a feeding frenzy, a rare occurrence when a large group of sharks all go after the same prey. Caribbean reef sharks, for example, follow a distinct pecking order in which the biggest shark eats first.

  27. Great white sharks are picky eaters. Their diet requires lots of fat, and after one bite a great white shark can determine whether or not the meal will satisfy its nutritional needs. If it doesn’t, the shark will leave the rest and swim away.

  28. A new species of hammerhead shark was discovered in 2006 through DNA testing. An official confirmation is still in the waiting.

  29. Sharks are especially susceptible to the moon’s control of ocean tides. The phase of the moon can affect sharks’ eating habits and draw them closer to shore.

  30. The average shark lives to be 25 years old, but some like Spiny Dogfish Shark can get as old as 100 years! They live so long because their chances of contracting a disease are low. Their skeleton is made up entirely of cartilage, which drastically lowers the likelihood of developing a tumor and strengthens their immunity.

  31. Sharks respond to a sound known as a “yummy hum.” It’s not an actual hum, though. It’s an infrasonic sound (one that’s too low for humans to hear) that injured fish make, drawing sharks to an easy meal.

  32. Every once in a while, a female shark can reproduce without any contact from a male, an act known as parthenogenesis. Scientists have only documented a couple of cases of parthenogenesis, but some suspect that just about any female shark can get pregnant on her own in the right circumstances.

  33. Sharks living in frigid waters can heat their eyes using a special organ next to a muscle in their eye socket. This ability enables them to keep hunting their prey in extreme temperatures.

  34. Great white sharks off the coast of Seal Island, Africa, are known to jump almost 3 meters in the air to catch unsuspecting seals.

  35. Between 1962 and 1968, all hot gods sold at Yankee Stadium were made from shrak meat. Pig numbers had rapidly decreased along the east coast of the US as a result of an outbreak of Blue Eye disease. Once the pig population's numbers were restored, hot dog manufacturers returned to the original recipe of pig likps, eyelids and ani.

  36. The reason sharks often swim with their dorsal fin out of the water is because this fin is allergic to salt. When submerged, the fin is very itchy but air has a soothing effect on the irritation.

  37. At birth, the oceanic whitetip shark is perfectly proportioned, but less than 5 cetimeters in length. It remains this size for one week before growing a staggering 2 - 3 meters in a just single day! Many home aquarium owners in the 80s to 90s have mistaken the baby oceanic whitetip for miniature teabag shark, and woken up to find a fully grown "man-eating" shark thrashing around thier house...

  38. In Tok Pisin language - the most widely spoken language in Papua New Guinea: "Shark" is the most offensive possible curse word, so inmage you say "SHARK off" instead of "F**K off.

  39. Bull shark is a type of shark that is best known by its aggressive behavior, since this species has many attacks on humans registered. It can be found in warm, shallow waters of all oceans of the world, and it can survive in brackish water (mixture of salty and fresh water), but they can be also found in the Amazon and Mississippi rivers and in various lakes.

  40. Most of the hammerhead sharks are gray or brownish. However, the smooth hammerhead shark is olive green or dark gray-brown on the top and white underneath. Their pectoral fins have black tips.

  41. Sharks also drop thier teeth, but when one falls, another replaces it. Shark Teeth are very dynamic. The teeth of a shark are in consecutive long rows. When they lose one tooth, a new one from the back row come forward to fill the slot, this will never ends till the shark dies, and a shark can grow more than 30,000 teeth in a lifetime.

  42. The blood of the sharks has a high urea content, which can reach 2.5% in a shark (in other vertebrates, it is only 0.01 – 0.03%) makes the shark’s blood isotonic to sea water. And sharks can adjust their kidney function so that larger amounts of urea pass with the otherwise diluted urine.

  43. When sharks sleep, they keep thier eyes open. Only one side of the brain sleeps at a time so that they can continue the breathing cycle while they rest. And like i alreayd siad, they still keep swimming.

  44. The shark skin has been vital for its survival, because it's very rough to give them protection from other animals including other sharks; this is why shark skin was once used as sand paper. Whale shark's skin can be up to 10 cm thick.

  45. Tiger shark is one of the largest that inhabit the oceans only smaller than the whale shark (Rhincodon typus), the basking shark (Cetorhinus maximus) and the great white shark (Carcharodon carcharias). It reaches a maximum length of 7.5 meters but on average measures between 3 and 4.2 meters long while its weight ranges between 385 and 635 kilograms.

  46. Tiger shark in the mating period. During that time it meets with other tiger sharks and groups establishing a social hierarchy based on their size, so larger individuals have access to prey before than the small ones. Once the elders are satisfied, the others can approach the carcasses of the unfortunate prey. Despite this dominating behavior, violence between members is almost nil.

  47. Both male and female Tiger sharks have multiple sexual partners throughout their life, which is about 27 years in the wild. The female reaches sexual maturity around eight years old and the male at seven years old.

  48. Bull Shark prefers loneliness than the company of other sharks of its species, so it hunts by itself. Probably their most notable behavior is that they can tolerate freshwater.

  49. The great white sharks jump out of the water sometimes to look the surrounding and look for prey. They are not aggressive with their own species, but if they feel threatened, they may bite his antagonist as a warning.

  50. The great white shark is a fish mostly solitary although it can reunite with others of its same species. In their groups, it is likely that there is hierarchical dominance, and the females are in the lead, but among all, large individuals dominate the small ones, and the residents of the group for a long time dominate the newcomers.


This article is written by @Dive and Cruise, hope you like it ;-)

Sources:
Wikipedia - Great White Shark
Iucnredlist.org
Arkive.org
Sharkopedia.discovery.com
Sharks-world.com

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