How Sharks Hunt for Food


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  • That the scent hits both nostrils at the same time…which they do, but sharks sense one before the other. Have an abstract.
  • Hits right nostril, they go to the right. Hits the left nostril, they go to the left. Fish locate odor sources by a process known as eddy chemotaxis (tracking of odor and turbulence. Odor plumes are dispersed in patches. Are left behind in the wakes of boats. Odor plumes are complex 3-D structures used by animals to locate food. From natural selection, this adaptation became a primary trait for sharks to maintain homeostasis (internal balance). Without it the would not be able to find food. Adaptations aren’t perfect, but they work. OVERVIEW OF HUNTING HABITS.
  • The lateral lines are literally sensory organs used to detect movement in the water. They are visible faint lines that run down the sharks sides in the vicinity of the gill covers to the base of the tail. Wiki Receptors are made up of tiny hair, similar to the make-up of the human inner ear. Common origin. Almost the same way in which humans can feel air flow on the small hairs on their face.
  • They sense the timing of the scent hitting one nostril and another. (Can be as small as a tenth of a second). Hits the right nostril, they go right. Hits the left nostril, they go left. Odor itself has no directional properties, animals instead use a variety of senses. Specific genes tell them where to go, inherent movements.
  • Organisms make free decisions. They have conscious thought, but it is different from humans in the face that it is much more direct and focused on one objective (sharks: food). There is no language just instinct. They are aware of themselves and just existing (achieving homeostasis).
  • Benthic shark (sharks that dwell near the ocean floor). This mathematical law can be define or thought of as Diel Vertical Migration.
  • How Sharks Hunt for Food

    1. 1. Sharks: Their Hunt for Food. By: Jon El Kordi-Hubbard BIO 003 03L Cafferey S
    2. 2. Scientists’ Prior BeliefS Used to be thought that the concentration of the smell entering the nostrils was compared by sharks and used as a navigation tool.
    3. 3. Overview of Hunting HabitsS Sharks are “scent hunters” S Use noses to seek out preyS Distinguish which nostril the smell enters first S Then swim in that direction S Eddy ChemotaxisS Sharks entire bodies function as a giant nose S Able to pick up the “shape of the smell”
    4. 4. Odor Plumes
    5. 5. Boston University Odor ExperimentS Scientists ran a stream of squid odor through a circulating H20 tank and noted the sharks ability to find the source.S 1. With no eddies or plumes the shark almost always failedS 2. Then they placed a brick behind the scent, thereby jumbling the flow of the scent, the shark fared much better.
    6. 6. Hunting Habits cont.S On the sides of the sharks nerve-packed stripes called lateral lines.S These lines can detect vibrations made by other organisms inH20.
    7. 7. Foraging StrategiesS Sharks use timing to orient themselves in the right directionS “Timing is a better tool because scents can travel through water in random, chaotic, patterns” S Jayne Gardiner.
    8. 8. OtherForagingStrategiesS “Levy walks” are done by sharks S Long wanders in specific locations (based off instinct).S Sharks use math to hunt S They do not move randomly
    9. 9. Sharks make free decisions…S “Organisms, when allowed to make free decisions, seem to end up obeying some kind of mathematical law.” S GandhimohanViswanathan (University of Glascow)
    10. 10. (DVM) Diel Vertical MigrationS Large movements by predatory fish (i.e. benthic shark) to highly concentrated areas of foodS Instinctive decisionsS Evolutionary trait S Energy conservation (easier to hunt in large concentrated areas of prey rather than small).
    11. 11. ConclusionsS Sharks hunt using scentS Attack success is directly related to prey densityS Use full body nose to detect movements of preyS Instinctive creatures that do not move randomlyS DVM v. Eddy Chemotaxis are both used by sharks
    12. 12. Work CitedS Bhanoo, Sindyan N. "In Hunt for Food, Sharks Have a Sense of Timing." The New York Times 14 June 2010: D3+. Print.S Heat, By Body. "Great White Sharks Hunt Like Serial Killers : Discovery News." Discovery Channel : Science, History, Space, Tech, Sharks, News. Web. 30 Nov. 2010. < attacks.html>.S Sims, David W., and Victoria J. Wearmouth. "Hunt Warm, Rest Cool: Bioenergetic Strategy Underlying Diel Vertical Migration of a Benthic Shark." Journal of Animal Ecology 75 (2006): 176-90. Ebsco Host. Web. 22 Nov. 2010.S Witze, Alexandra. "Sharks Use Math to Hunt Their Prey: Marine Predators Cruise the Seas Using Fractal Principles." Science News 3 July 2010. Print.