1 / 26

Sharks

Sharks. Lemon Sharks. Information.

felton
Télécharger la présentation

Sharks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Sharks

  2. Lemon Sharks

  3. Information Statistics• Mature length – 7-9 feet• Mature weight – 200 lbs• Lifespan is approximately 20 years• Found in subtropical, shallow waterIt’s called Lemon Shark for its pale yellow-brown color. This shark is found in Atlantic waters, and the Gulf of Mexico and the Caribbean. It can be aggressive if provoked, but is generally thought to be of little threat to humans. According to the International Shark Attack Files, there have been 10 recorded bites on humans by lemon sharks. Statistically speaking, you are more likely to drown when going to the beach than to be bitten by a shark - any shark. On United States beaches in the year 2000, there were 132 beach fatalities. Seventy-four of the fatalities were caused by drowning. There were twenty-three shark bites, total. Not all of them were fatal. The chances of drowning while at the beach are 1 in 3.5 million. The chances of being bitten by a shark: 1 in 11.5 million. Just food for thought.According to the Florida Museum of Natural History, there is some evidence that two separate populations of lemon shark exist within the western Atlantic Ocean; one in the Caribbean and one in the Gulf of Mexico.

  4. Picture

  5. Video

  6. Great White Sharks

  7. Statistics:• Males reach maturity at 11-13 feet• Females reach maturity at 15-16 feet• Their adult weight averages anywhere between 1,500 and 2,400 lbs• The largest of the White sharks tend to be around 20 feet in length, weighing up to 4,200 lbs• They are primarily solitary hunters• They usually prefer colder water• Found in every major oceanHunting:All sharks are good hunters. It’s what they do. But I am fascinated by what I’ve learned about the White shark’s hunting techniques and abilities. Their hunting is anything but random and mindless. There is a process involved. They are stealthy. They are smart. They hunt using many senses. It is commonly known that sharks can smell blood, but that is only part of it. One of my favorite episodes of shark week was one where I was first introduced to the ampullae of Lorenzini. The ampullae of Lorenzini are located in the nose or front of the face. They are special sensing organs called electroreceptors, forming a network of jelly-filled canals. They help the shark to sense electricity fields in the water. Prey gives off electricity. The sharks can sense that electricity, in combination with the smell of dead fish or blood. They also use their eyesight. Their eyesight is so keen that they can even hunt by moonlight. They can detect sound waves in the water using a sense organ called the lateral line. The lateral line runs down the sides of the shark, on either side of the dorsal fin from the gills to the tail.A shark will stalk its prey. It will sense it from quite a ways off, and watch it to see what it is and what it might do. If it decides the prey is worthy of a closer look, and potentially becoming a meal, the shark will drop down to the ocean floor, and ambush its prey at speeds of up to 20 miles per hour. It hits its prey from the bottom, with such great force that sometimes the shark (and the prey) will breach the water, making itself visible to anyone around.Sharks don’t have hands, so they test things out with their mouths. On humans, they usually inflict what is called an exploratory bite. They are checking it out to see what it is, and if it’s food. I believe that a White shark could consume pretty much anything it wanted to, but they are actually more picky eaters. Due to their large size and constant activity, they prefer to eat high-fat meals, such as seals. When they bite a human and realize it’s not a food item, they usually let go. I don’t believe a human could survive a Great White attack if the shark’s intent was to eat. Information

  8. Picture

  9. Video

  10. Angel Shark

  11. Information Statistics• Commonly grow to a length of 5 feet• Found in shallow tropical waterThe angel sharks are an unusual genus of sharks with flattened bodies and broad pectoral fins that give them a strong resemblance to skates and rays. The 16+ known species are in the genus Squatina, the only genus in its family, Squatinidae. They occur worldwide in temperate and tropical seas. Most species inhabit shallow temperate or tropical seas, but one species inhabits deeper water, down to 4,300 ft.FeedingAlthough this shark is a bottom dweller and appears harmless, it should be respected due to its powerful jaws and sharp teeth which can inflict painful lacerations if provoked. It may bite if a diver approaches the head or grabs the tail. If they are left alone they will not attack.They bury themselves in sand or mud lying in wait for prey, which includes fish, crusteaceans, and various types of mollusks.

  12. Tiger Sharks

  13. Information Statistics• One of the largest species of shark• Commonly reaches 10-14 feet in length• Can weigh as much as 1,400 poundsIt is known for its spots, which can also look like stripes. The markings are vivid in young sharks, but fade as the shark matures. Its other common names are leopard shark, maneater shark, and spotted shark. This shark is big, strong, mean and scary. Ok, maybe not mean. To say its mean indicates that there’s some sort of malice in its mind. Tiger sharks are non-discriminate hunters. Unlike the Great White, they will eat just about anything. Most of the stories you would hear about sharks ingesting non-digestible items, come from Tiger sharks. Their stomach contents has been known to include a chicken coop, a roll of tar paper, a license plate, tires, and a suit of armor. These sharks literally will eat anything.Tiger sharks typically prefer murky waters in coastal areas. Tiger sharks undergo seasonal migrations. They move into temperate waters from the tropics for the warmer months and return during the winter. These sharks also make long oceanic migrations between islands and are capable of traveling long distances in a short amount of time.ReproductionThe gestation period ranges from 14-16 months, at which time a female can give birth to anywhere from 10 to (get this!!) 80 pups. Eighty!! No wonder they don’t stick around to mother them! When pups are born they are between 12 and 18 inches in length.Danger to HumansThe Tiger shark has been implicated in 158 attacks worldwide between 1580 and 2008. Their eyesight in water is ten times better than human eyesight. Not to worry though, their main food items are fish, crustaceans, sea birds, marine mammals and sea turtles.The tiger shark generally hunts at night, and is a solitary hunter. It is an opportunistic hunter, taking advantage of anything it thinks will be an easy meal. It has been known to feast on dead whale carcasses as well as its typical prey items.

  14. Nurse Shark

  15. Information Statistics• Can reach lengths of 14 feet• Can weigh up to 330 pounds• Found in tropical and subtropical waters• Bottom-dwelling sharkWhat I find interesting about theNurse Shark is that they look a lot like a catfish. They are nocturnal. Unlike most sharks, Nurse sharks are able to breathe while stationary by pumping water through their mouths and out their gills. Their prey primarily consists of bottom fishes and invertebrates including lobsters, crabs, snails, octopuses and squids. They seem lethargic during the day. However, at night they transform themselves into determined predators that routinely knock over coral heads and big boulders to get to their intended prey that they “vacuum” into their mouths while using a powerful, suction-feeding technique. This feeding method has earned them the nickname “sucker shark”.Here is an interesting video about how nurse sharks bite.To clear up a point of potential confusion, the gray nurse shark (a.k.a. sand tiger and ragged tooth) is not a type of nurse shark. The gray nurse is described in a different family of sharks than true nurse sharks. According to the International Shark Attack Files the nurse shark has been attributed with a total of 27 recorded attacks since 1580 with no deaths reported.

  16. The Galapagos Shark

  17. Information Statistics• Can grow to 12 feet in length• Can weigh as much as 200 pounds• Found off tropic oceanic islands• Lifespan is at least 24 yearsAccording to the International Shark Attack File, the Galapagos shark has been responsible for one fatal attack on a swimmer in the Virgin Islands. Inquisitive and persistent, the Galapagos shark is regarded as dangerous to humans and diving unprotected is not advisable in areas where they are abundant. They are known to approach close to swimmers, showing interest in swim fins or hands, and are drawn in large numbers by fishing activities.FeedingThis shark feeds primarily on bottom-dwelling fishes as well as on squid and octopus. These fish include eels, flatheads, groupers, flatfish, and triggerfish. The Galapagos shark displays threat gestures to warn competitors in the search for food. Large sharks are potential predators of the Galapagos shark. Cannibalism is also reported within this species.ReproductionGalapagos sharks are "viviparous", or livebearing, with embryos nourished by a yolksac-placenta during gestation. Mating and birth occurs early in the year within Hawaiian waters. Female individuals often have mating scars from males biting the gills, fins, and body. After gestation during which the embryos develop inside the mother, live birth results in a litter size of 4-16 pups. Each pup measures 24-31 inches in length. The pups stay in shallow water nursery areas to avoid predation and cannibalism from members of their own species, eventually moving out to deeper waters as they mature. Males mature at 7-8 feet long and 6–8 years old, while females mature at 7½-8½ feet long and 7–9 years old. Neither sex is thought to reproduce until 10 years of age.

  18. The End

More Related