Sharks are fish groups of Chondrichthyes, body hydrodynamic easy displacement, from 5 to 7 gills along each side or near the top (the first slot of the eye called spiracles), small spiny skin wrapped the body against parasites, the teeth in the mouth can grow again. Sharks include species with only the size of a hand, as Euprotomicrus bispinatus, a live fish under the sea is only 22 centimeters long, to giant whale sharks (Rhincodon typus), the largest fish with a length of 12 meters (39 ft) equivalent to one whale but only creatures eat plankton, squid and small fish species. Bull shark (Carcharhinus leucas) are the most widely known thanks to the ability to swim in both fresh water and salt water, even in the delta. Sharks are supposedly appeared over 420 million years ago, before the era of dinosaurs appear.
Sharks spawn eggs, but most species are nurtured in the mother's body until they hatch. In some species the remaining eggs are often coalesce into a beam and is fastened to a robust and discreet place. Some sharks are unfaithful to their partners, only one lifetime sexual partner. If a child dies, the other pair that will not paired with any other shark or transgender will continue to maintain the breed task.
Smell perfect and good eyesight plus ability to sense electric fields of animal fixed for shark sea kings throne. With this sense, a shark can identify the smell of blood, or urine of prey kilometers away. So many people think that if they do not bleed or surfing beach for fear of being attacked. But the smell is very good because of the sharks that it easily distinguishable from human blood and blood prey in the wild, so it can not be confused and will not attack because sharks do not consider humans as prey. Most of the attacks are so wrong about the shark surfing or swimming in the sea as seals or sea cows.
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