Curiosities About Sharks

Steven Spielberg's movie "Jaws" in 1975 provoked so much terror amongst people that, since then, sharks suffer an indiscriminate hunt that has endangered many species of sharks that are nowadays close to extinction. Although it is an animal that may be dangerous in some circumstances, their voracity has been exaggerated. There is little number of species that are really dangerous. There are many legends around them, but did you know that... The biggest shark in the world is the whale shark that reaches 23 meters long (68.9 ft) and is vegetarian. The smallest shark is the Squaliolus laticaudus, that is not longer than 25 cms. There are more than 300 species of sharks. Photo by Allan Lee Sharks already existed when dinosaurs did, and they are 400 million years old. One of the most curious sharks is the bull shark, that can leave the sea and travel against the current of rivers for kilometers inside the Amazon River. The most developed sense of sharks is smell. Sharks have hundreds of teeth that change all along their life constantly. Sharks may lose about 30,000 teeth until they die. Some sharks need to be constantly swimming to be able to breath, and swim even when they're sleeping. But other species of sharks can remain still in the depth waiting for a prey. Teeth of sharks are not attached to their jaws. They grow inside the gum itself, but not to the bone. The hardest part of sharks is the teeth, because their skeleton is made of cartilage. The fastest shark is Isurus Oxyrinchus (Mako shark), that reaches up to 74 km/h (46 mph), and can jump outside the water up to 9 meters high (28 ft.) Female sharks can have up to 12 fetus, although many times just one will be born. Most sharks reach sexual maturity when they're 12 to 15 years old. This is the reason why many species are in danger of extinction, because they're hunt before that age. Not only the bull shark can enter the rivers, there's a couple of species that can do the same in the Orinoco, Nile, Ganges, Mississippi... These species are the most dangerous. Some sharks can detect their prey up to 30 Kms of distance. The skin of sharks have a very particular structure made of tiny scales that have the touch of sandpaper and this makes them swim faster. -Emma Alvarez- © 2008 by Emma Alvarez. Link to this post without copying the text. Some Related Posts: If you liked this post, subscribe to Emma Alvarez Site or give yourself a gift Stumble it! Add me to your del.icio.us network