Great White Shark Dakota King Marine Biology 1070

Great White Sharks  Carcharodon Carcharias  Known as the Great White, White Pointer or White Death. Its known as the worlds largest predatory fish.  Their objective is not to terrorize humans, they are much like us, the look for food, breed and stay out of danger.  Their design has only changed a little bit here and there over millions of years to adapt to their changing surroundings.

Ecosystem  They can live in surroundings like open water, weedy shallows, muddy dark depths, sandy or rocky coasts, and tropical and even polar temperatures.  They can live all over the world from coasts of America, the Gulf of Hawaii, South Africa and West Africa to Scandinavia, the Mediterranean Sea, Australia, New Zealand, Japan, and the eastern coastline of China and Southern Russia.

Life  Baby sharks are called pups. They hatch inside the mothers body and get food directly from her. Sharks that give birth in this matter are called viviparous sharks.  Sharks can live 20 to 30 years old, but some scientists think that they can live up to 100 years old, but it has not been proven.  They can reach up to 20 feet and weigh up to 5,000 lbs.  Scientifically there is no way to determine the life span of sharks.

Life Continued  They are gray or bluish- gray in color, with a white underbelly. The color helps them get closer to prey without them being noticed.  From below, the white underbelly reflects the surface so its easier for them to sneak up on their prey.  With the grayish color on the top helps it blend in the dark water and harder to spot from on top of the water.

Feeding behavior  They sense their prey in distress by using their lateral line that runs from their head down to their tail. It picks up vibration from the fish and uses it to locate where it is from up to a mile away.  They have great eyesight, even better than ours. They have a reflective layer inside their eyes that helps them see better in the dim light when they are locating prey and also can see colors.  They eat dolphins, sea lions, big bony fish and penguins. They also go after dead animals that float on the surface.

Feeding Continued  Their only real weapon is their mouth. The two most important parts are the teeth and jaws. They do not chew their food, they just gulp it down whole. The only use for their teeth is tearing and biting food into small pieces.  The upper jaw is connected to the skull and moves out when the shark attacks their prey so that they can latch on.  The lower jaw puncture and hold the prey, while the upper jaw slices it. FUN FACT:  Warning Bells: If your upset a shark in its territory, it usually warns you before attacking. It shakes its head and with its back hunched and snout up. This is called Agonistic display.

Survival  Sharks have a special skin cover. Unlike overlapping scales of a fish, shark skin is covered with small tooth-like scales. They are called Denticles.  In rare cases they are preyed upon by orca whales (killer whales). They can flip the great white shark upside down to induce tonic immobility for fifteen seconds causing the shark to suffocate and die.  Other than the orca whale, the shark is the biggest predator in the ocean.

Human Impact  Sharks keep the ocean healthy because they keep different species from becoming overabundant. They scavage for dead animals to keep the ocean clean. They keep other species more fit and weed out the sick and weaker individuals.  Shark fin soup is considered a delicousy in Asia and are making a disaterous impact on sharks. Humans cut the fins off of sharks then throw them back into the water dead or alive. The US has esimated about 73 millions sharks are killed annually.

Human Impact Continued  Shark Nets are set on the coast of Africa and Australia. They are meant to protect swimmers from rare attacks, but the nets are entangling, suffocating and killing sharks.  Sanctuary: Off the coast of California’s Farallon Islands, NOAA is protecting Great White Sharks. Countries like South Africa, Namibia, Australia, New Zealand, Isreal, and Malta are now fully protecting Great whites and their national waters. The internaltiional organization CITES implemented a ban on all international trade of products on Great White Sharks.

Scientific Article “Great White Shark now more endangered than tigers with just 3,500 left in the oceans”  Sharks are known as one of the deadliest animals on earth. According to a new study, great white sharks are one of the most endangered. Wildlife experts say that there are fewer than 3,500 of them left. The new estimates of their population were published later this year by scientist at Stanford University who have been studying their migration and have been tagging sharks with radio transmitters. They found that great whites are incredible long distance swimmers, capable of traveling 12,000 miles in 9 months. Dr. Ronald O’Dor, senior scientist at the Washington based Census of marine life said “the estimated total population of the great white sharks in the world’s oceans is actually less than the number of tigers”.  Although they were once thought to be “eating machines”, and people thought that they didn’t need to be saved, are now seeing that they are become rare and are a wonderful species and that we need to keep them in our ecosystem since they are a great part in our world.

Sources  Scientific Article: “Great White Sharks now more endangered than tigers with just 3,500 left in the oceans…” - White-Sharks-endangered-tigers-just left-oceans.htmlhttp:// White-Sharks-endangered-tigers-just left-oceans.html  Websites: shark/human-connectionshttp://ocean.si.edu/ocean-life-ecosystems/great-white- shark/human-connections  Books: - Wonders of Living; Discover Sharks - Cousteau’s Great White Shark; by:Jean Michael Cousteau and Mose Richards - The Encyclopedia of Sharks; by: Steve and Jane Parker