Imagine you're at sea motorboat ride . then there is a fin sticking out the side of your boat . You relax because she thought it was a dolphin because no swim as fast as they are . after a few seconds , the creature jumped out of the water is very high. Now you can see the whole body and you realize that it is ... SHARK !

Sharks are an accomplished swimmer ; they can swim as fast as 40m / h . The most rapid mako shark . for speed range, the speed can reach 60m / h . This shark is also a good jumper . he could jump to 6.5 yards above the water surface .

One World's oldest creature

100 million years before the age of dinosaurs , sharks have been swimming across the ocean . Sharks are the oldest lived about 400 million years ago . since 60 million years ago , there were some shark family that does not change too much when you compare it to the sharks that live on today .

Variety of species of sharks

One shark is not the same as the others . Overall we just know there are 360 species of sharks . half of them live on the ocean floor and they never came close to humans . The others stayed at the ocean surface. the types of sharks in all shapes and sizes . No sharks were only 6 inches in length , and there are also extends for 15 yards . The shark is a shark usually the quietest . for example, whale sharks or giant shark . they only eat plankton and small crabs .

other sharks only eat fish , crabs , starfish and other small sea creatures . Very dangerous sharks is the blue shark , greenland shark , riff shark , hammerhead sharks and the great white shark or a mako shark. they could eat seals to polar bears .

Why can not they fall to the bottom of the water ?

Sharks Swim NOT have tools , air filled body organ Yang , Yang is usually used the fish to float in order NOT Drowning review . but sharks have bones SPECIAL Made Of cartilage . Slightly cartilage was MORE than Yang Lightweight materials generally form the composition of bones Sales manager Yang makes them easier to review float . Also Sharks have oil The Light in the hearts of their hearts Severe help them NOT Falling Into Air Base .

Sharks could sink !

Did you know that sharks can drift ? some types of sharks have to swim continuously , so that way they can get oxygen , because the water meets the grating them . therefore , when they are caught in a net or a narrow cage , they can die . other sharks do not have problems like this because they can press water into the grilles them to come out .

Family

Sharks do not feel the life of the family . they live alone , hunting alone and do not care about their children . they are loners . only at the time of reproduction , sharks meet in large groups . sharks each other find their soul mate because the females secrete a kind of scent .

Sharks give birth in three ways . some sharks such as cat shark or bull shark , birth by laying eggs . The egg shaped like a cube . on each of the four corners there is a kind of thread that binds them with water plants until the baby shark was ready to leave its shell .

On the other sharks , such as blue shark , hammerhead shark , gray shark or shark saw , gave birth to their children .
then the other way is the way among lay eggs and give birth . sharks such as whale sharks , white sharks and tiger sharks or carpet shark carry their eggs in their bodies . When the baby is ready, they come out of their shell eggs is very strong, but still inside their mother 's body . and that's when the mother gave birth to her baby .

shark pregnancy can take a very long time . for gray shark , the time it takes a little longer than one year and to curl shark could take two years . the reason for this long period is to produce very strong baby who lived only win the competition , determine which babies have a better chance to survive .

some baby sharks do not like their brethren . could have been from 60 infants of the tiger shark , there are only two left in the end. This happens because the baby to eat each his own if they do not have enough food . to suppress this incident , some sharks make a separate room for each baby in its mother's body . that way they can not kill or hurt others .

Sharks do not take care of her baby . they must be independent . they do not learn from their parents how to hunt , how to avoid enemies , or how to reproduce. they learn it from instinct. inevitably , they must be an adult as soon as they were born in order to continue living .

Port Jackson Shark Egg

if they are not eaten by the enemy or died of disease , sharks can live in a very long time span , but their age varies depending on the type of shark it was . Cat shark , for example , can live for 8 years . Dornshark can live for 24 years , and other sharks can live on average for 30 to 50 years . sharks live record of the longest ever known up to now is 70 years old .

Sharks do not know toothache

The most important tools for sharks is their teeth. if you ask someone who survived a shark attack , he will tell you that the bite did not hurt . But shark teeth sharp as a razor and hard as iron . and the jagged surface like the chainsaw . he can cut thick bone easily and quickly .

We may envy the shark's teeth . they never felt a toothache . Shark teeth grow at an extra layer of skin where the sharks do not feel pain . when cutting the bone , the teeth can be cracked or broken . but the shark was not a big deal . in a single row of teeth , they can grow five rows of teeth again . within a few hours cracked or broken tooth was regenerated . on the skin surface specials , new teeth are always growing again. Tiger shark for example , they usually grow 1,400 teeth in 10 years . riff shark bite often large stone to find hidden food and use over 10,000 teeth in a period of 18 years .

Great White Shark's teeth

many shark not only has teeth in his mouth , but also the small teeth on her skin. teeth on the surface of the skin is a natural tooth that has been in their care since the first. scientists investigating shark embryos and found that the teeth in the mouth is made of the teeth of the skin during pregnancy . teeth on the skin works like a paper trimmer . if there is a shark passing and nudging you, he can make your skin scraped and bloody . and often the blood that increase the appetite of the sharks.

Different senses

humans usually have five senses . vision, hearing , taste , touch and smell . Sharks also have a sense of this but the way they work differently . eyesight is not good sharks , rays day eye does not get into the water so deep , shark eyes only works at close range .

usually a shark using his ears to realize something and measure the distance. sharks not only have two ears on the head, ears form of two lines on the front of his head to the tips of the fins. The long lines have small holes where water seeping in. the sharks could hear a different sound waves in the water as we can hear sound waves that vary in the air. each movement creates noise, but not everyone can hear it. the movement of water creates a very soft sound waves. These sound waves are not audible to humans, but is able to be heard properly by sharks. they can find out where the location of their prey using their sense of hearing from a distance. and so the distance approaches, sense of vision began to take over. The new shark attack when she heard the clatter felt as prey and most often is when he smelt the smell of fresh blood.

shark has two noses on each side of his head . noses have two holes , each of which serves as the gills of fish . water passes through their noses continuously so that the sharks could be aware of any changes that occur . the sense of smell shark very, very good . for example , the great white shark can smell one drop of blood that falls in the ocean .

when a shark was not sure prey tasted good or not , he uses the four senses , taste . rather than the tongue , shark using the whole body to feel the delicacy of prey. touching the shark prey will prove whether this is good or not .

When a shark attack , it automatically call the other sharks because the smell of fresh blood in the water . more than 20 other shark could come and eat wild party begins. now the shark will eat whatever they find and it does not matter whether edible or not . they do not just bite their prey , but biting box , wires , stones , ship . but in this situation , they will not hurt or kill each other .

even if the water is concentrated by blood and they can not see anything , they ultimately serve five senses . This sense is similar to an electric sense , the whole head of this shark has a very small hole . in every hole it contained very fine strand of hair that can receive electrical signals within 1 yard . all animals avoid these electrical signals , for example , through the movement of muscles. When the shark realizes there is an electrical signal from the other sharks during their wild junket , he was immediately aware of it and does not bite.

Friends and enemies

believe do not believe , the shark had an ally . among others pilot fish , they are not interested in leftovers sharks , they eat fish lice , crabs are small, blood-sucking worms that normally live on the skin surface sharks. then this pilot fish cleaning their shark and as gratitude , sharks do not prey on them . sharks and even protect the pilot fish of most of their predators because predators were afraid of the sharks . friendship between the sharks and other fish is the same as it was . some fish clean the skin of sharks while the shark continued his odyssey . overall we know there are 10 different species of fish that live in a symbiotic mutualism with a shark .

the relationship between sharks and dolphins have two sides . the one hand they can live and hunt together peacefully. but on the other hand , sometimes sharks attack dolphins being alone and sometimes in teams of dolphins attacked sharks. utilize their heads are hard and sharp , shark hit the stomach or gill shark and make pain . Sharks could have died from the wounds he received it .

Shark is indeed very dangerous . but they are not the king of the ocean . they have a lot of enemies , whales are often much greater than the shark , is one of them . pod of killer whales or whale shark can swallow whole. do not forget the giant octopus that can be harmful to sharks . with their long tentacles can be 9 to 13 yards , they can catch the sharks and eat it .

Other animals such as swordfish or sea lions can also hurt the sharks and cause serious injury . Sea snakes are also very dangerous with their poison that can kill other animals immediately. therefore avoiding sharks usually a sea serpent .

apart from that there are also sharks that could eat other sharks , especially gray sharks that eat all the sharks are smaller than you e 3 yards . great white shark also eats up all the smaller him.

The most dangerous enemy of sharks , which are also harmful to other animals enemy is none other than the man himself. fishermen catch sharks to take the meat , sometimes they just take any fins and the rest used for food , his skin as raw materials , and some partitions body rich in vitamin used as a drug .

many people think that the shark is the beast should be killed . although it is true that sometimes sharks attack humans, but they do not realize that more people were killed due to lightning, snake bites , bee stings , not including vehicle accidents . but no one thought ridiculous to ban the use of cars . people kill sharks because of hate , to protect the coast , because they thought it was a nice place to vacation .

Usually, people kill 4.5 million sharks a year. it would be the same if the shark could kill half the people who live in a city for a year . therefore drastically reduced shark populations in the world. in the last 10 years, some countries try to protect sharks . now the number of sharks to be killed has been limited. although they started to protect sharks , many of them are still in danger of extinction today.