The sea is an ocean of mysteries, and none of them is more fascinating to me than the creature that some call ‘man-eater’ or ‘white death’. It is the vision of terror summoned by an active imagination when one swims out too far from shore, a vision that evokes mankind’s collective nightmare of being eaten alive. It is Carcharodon carcharias; it is the Great White Shark.
What do Great White Sharks look like?
The Greek name, (Genus species) for the Great White Shark is Carcharodon carcharias carchar meaning ragged and odon meaning tooth. It is in kingdom-animalia, phylum-chordata, subphylum-vertebrata, order-lamniformes, family-lamnidae, and class-don t know. The Great White Shark s body can grow from 4 ft to 23 ft. It s skeleton is cartilage and 63% of the body is muscle. Sharks have a pointed snout that extends forward and over a crescent-shaped mouth set with triangular shaped teeth. The Great White Shark can have 20 rows of saw blade like teeth. The female shark is larger than the male. Only a few species, including the White, the Mako, and the Tiger shark, have the large fearsome teeth popularly thought of as typical sharks. The Great White Shark s swimming speed can be up from 20 to 30 MPH. Color consists of blue on the top and white on the bottom.
Sharks are sensitive to light and can detect objects even in murky water. Some have a mirror like layer under the retina that allows more light into the eye. Sharks do have ears, but the role of hearing in the shark s location of prey is not well understood yet. A shark can detect sound waves and disturbances in the water with its lateral line or lateralis system. This is a series of thin canals, filled with water that runs along the side of the body. The canals are attached to nerves that send signals to the brain. Sharks can also sense electricity and magnetic fields. Sensory pores located on the shark s head can detect prey s bioelectric field even if the prey is buried in sand. A shark can also detect the earth s magnetic field. Open-ocean sharks may use this information to navigate and orient themselves. The life span of the average shark consists of about 10 years. The shark s only line of defense is its teeth.
Where do Great White Sharks Live?
The great white avoids very warm or cold seas; it likes the water about 50-70 degrees F. It has been known to wander as far north as Alaska. The great white is found mainly off the coasts of North America, southern Africa, Australia, New Zealand, Japan, and parts of the Mediterranean.
What do Great White Sharks eat?
Predatory sharks have an array of prey detectors. As a great white cruises the ocean, it constantly monitors the taste of the water, changes in pressure, even electrical activity. Chemical traces in the water provide the first indication of a possible meal, becoming stronger as the shark follows the sensors known as a lateral line system, and as it closes range, it can feel the pressure waves generated by moving prey. The great white has no predators except for man. It is known as the top predator .
Great Whites are generally carnivorous. Their diets consist of fish, seals and porpoises and whatever they want. They generally prey on the sick or injured. The smell of blood will put a Great White into a feeding frenzy causing them to bite and eat just about anything. This includes cans, and garbage floating in the water. They will attempt to feed on these things just to eat.
Streamlining of a great white allows it to swim all day at low speed without wasting energy. This is important because the shark hunts large prey like tuna, other sharks and seals, which are widely scattered. The great white gives birth just like a dolphin, when it s ready to come out it shoots it out and you have a little baby shark. It stays with the mother a while and once it learns to hunt on its own it leaves the mother. The great white has a mutualistic relationship with the sucker fish . The fish hitches a ride and eats the algae off of the shark s back and the shark gets cleaned in the process. The great whites are solitary from each other, and hunt alone. The great white can t wait for a meal to swim into range, but must move on in search of prey. It also has to stay moving so the oxygen can run through its gills.
Feeding frenzies are stimulated by the smell of blood and cause the sharks to attack any object in sight or within reach. These frenzies are infrequent. It isn t really known whether these frenzies occur naturally or if humans studying their behavior provoke them. Great Whites are also know to attack humans at any time of the day in warm or cold water. Although most reports are from the daylight hours in warm, shallow water near the coasts. This is where large amounts of humans are in the water swimming. North America, Africa, and the Caribbean and Mediterranean seas are where most of the attacks are.
What special needs do great whites have?
Sharks must always keep swimming. If they stop, they will sink to the bottom and drown. This is because all sharks do not have a swim bladder, which is a small bag-like part of their body, which holds air. This swim bladder is found in most fish, but not sharks. They must keep the water moving across their gills to get oxygen at all times to breathe.
What causes Great White Sharks to be endangered?
The main cause of sharks to become endangered is man. In the hands of man, sharks will never be safe. Man will never understand them, and people are scared of things they don t know about. Man hunts these sharks for food or sport. Some scientists take them from the ocean for experiments and hurt them or put them back where they don t belong.
Could Humans have prevented sharks from becoming endangered?
Great White sharks are endangered because humans don t understand them. The sharks are seen as a threat whether or not they are at the time, and they killed for this. Also, we could make sure the sharks that are not killed or injured, that are captured for experiments.
In conclusion I think that the great white is a magnificent creature and we need to accept that if we see an animal we don t know much about or hear about attacking someone, don t hurt it or kill it. If it does bite someone it s because they were in is territory, and he mistook it for prey, the ocean belongs to the animals in it not humans. Humans think they control everything, including nature, and we destroy it. We take all wildlife for granted and should start to realize we are killing off the most precious things that the world has.