1. SHARKS: THE ANATOMY AND PHYSIOLOGY OF A PREDATORIAL MACHINE

2. Taxonomy Kingdom – Animalia Phylum – Chordata
Class – Chondrichthyes (sharks, skates, rays, sawfishes)
Order – 8 orders (Lamniformes (mackerel sharks))
Family – 30 families (Lamnidae)
Genus – 50+ genuses (Charcharodon)
Species – species (carcharias)
List of species

3. External Anatomy

4. Internal Anatomy

5. Feeding
Most are carnivorous but some are filter feeders (whale sharks, basking sharks)
Tiger sharks are referred to as the “garbage guts” of the shark world
Contrary to popular belief, most sharks are picky about what they eat
Great whites choose only animals with blubber

6. Respiration
Most sharks have to keep moving to move water over their gills
Water enters the gill chambers through the mouth or spiracles and exits through the gill slits.
Blood in the gill filaments absorbs oxygen from the incoming water.

7. Circulation 2-chambered heart
Blood flows from heart to gills to body tissues back to heart
Countercurrent heat exchange enables fast-moving sharks to be from 10 to 20 degrees warmer than the water around them

8. Senses
Hearing – have inner ear, attracted to low frequency sounds, can hear up to 0.6 miles
Vision – excellent, 10x more light sensitive than us, attracted to shiny and thrashing, can see 50 to 100 ft.
Taste – have taste buds, actually spit things out
Smell – excellent, function in only smell not breathing, can detect some chemicals as small as 1 part per billion
Feel – group of sensory cells along outside of body called the lateral line used to detect vibrations in the water
Electroreception – Ampullae of Lorenzini detect electric fields given off by living creatures

9. Reproduction
Mating is rarely witnessed, male bites onto dorsal fin and internally fertilizes with clasper while over top of the female
Can be oviparous (horn, swell sharks), ovoviviparous (mako and sand tiger sharks), or viviparous (hammerhead sharks)
Gestation period is very long from 9 months up to 3 ½ years

10. Shark Attacks
You are more likely to be killed by stepping in a sand hole and having it collapse than you are by a shark
Tips to avoid attacks:
Don’t swim during low light periods
Stay in groups
Be knowledgeable about the area you swim/dive/surf in
If you find one, leave it alone
Avoid looking like prey
Sharks are attracted to:
Blood, splashing and loud noises, shiny colors
International Shark Attack File

11. Ecology and Human Uses
Pilot fish, remora, and others clean parasites like copepods and flatworms off sharks
Integral part of the food chain:
fishes, crustaceans, mollusks, marine mammals, and other sharks
Sharks, elephant seals, and killer whales have been known to eat sharks
Behavior researched mainly for avoiding attacks
100 million sharks are killed every year by humans even though several species are endangered and illegal to kill
Humans use sharks for:
Research, recreation like fishing and viewing, and products like medicine, jewelry, tools, and mainly fin soup

12. Shark Facts
The 1st sharks appeared on Earth 400 million years ago well before the 1st dinosaur roamed the Earth
Avg. life span is 25 years
Sharks never stop growing
Largest shark = whale shark (50 ft. long)
Smallest shark = dwarf lanternshark (5-7 in. long)
Fastest shark = mako shark (30 mph)
Deepest diver = Portuguese shark (9,000 ft. or 1. 5 miles)
Longest migration = a blue shark traveled 3,740 miles
Only freshwater capable shark = bull shark (the Borneo river shark (Glyphis sp. B), the Irrawaddy river shark (Glyphis siamensis), the New Guinea river shark (Glyphis sp. C), the Ganges shark (Glyphis gangeticus), the Speartooth shark (Glyphis glyphis)
Highest note heard is 800 Hertz (or G above High C on the piano), so humans can hear many high sounds that sharks cannot
Lowest note heard is 10 Hertz (or 1.5 octaves below the lowest key on the piano). The lowest note a human can hear is 25 Hertz, so we miss out on some of the very low frequencies that sharks can detect

13. Man-eaters!!! Great white shark Tiger shark Bull shark
Hammerhead shark
Mako shark
Oceanic whitetip shark
Reef sharks, lemon shark,
blue shark, etc…

14. Vocabulary
Placoid scales (dermal denticles) = small outgrowths that cover the skin of a shark similar in structure to the teeth
Liver = organ for energy storage and buoyancy
Clasper = one of the modified, usually paired organs by which the male clasps the female during copulation
Lateral line = sensitive receptors that detect gentle currents and vibrations
Ampullae of Lorenzini = special sensing organs forming a network of jelly-filled canals that detect electrical fields in the water
Spiracle = provide oxygenated blood directly to the eye and brain through a separate blood vessel
Dorsal fin = fin on top that stabilizes and may provide protection
Pectoral fin = paired fins on the side that control steering and add lift as the shark swims
Caudal fin = locomotive limb at the end of a shark that propels it forward
Viviparous = live birth (get nutrients from mother not an egg)
Oviparous = eggs hatch outside the mother
Ovoviviparous = eggs hatch inside the mother then give live birth
Cloaca = opening shared by the genital organs, the urinary and intestinal tracts
Spiral valve = lower portion of the digestive tract that is internally twisted or coiled to increase the surface area, which increases nutrient absorption
Atrium = a large muscular chamber that serves as a one-way compartment for blood that is about to enter the ventricle
Ventricle = a thick-walled muscular chamber that pumps blood

15. Great white

16. Tiger

17. Bull

18. Great Hammerhead

19. Shortfin mako

20. Blue

21. Whale

22. Basking

23. Lemon

24. Oceanic whitetip

25. Nurse

26. Pacific angel

27. Australian wobbegong

28. Gray reef

29. Blacktip reef

30. Whitetip reef

31. Greenland

32. Spiny dogfish

33. Sand tiger

34. Thresher

35. Leopard

36. Goblin

37. Swell shark

38. Horn shark

39. Bonnethead