1. Sharks and Rays
Class Chondrichythes

2. Common Rays in Hawaii

3. Fish vs. Sharks

4. Sharks are Fish!....But Do not have bones 5-7 external gill openings
No gill cover
No swim bladder
Internal fertilization with claspers
Placoid scales

7. Form and Function Heterocercal tail = upper lobe longer than the lower
Strengthen and support tail for forward thrust
Teeth in rows
Teeth lack roots and often break
Easily replaced

8. Predominant dorsal fin
Placoid scales
Reduce drag, protection
Paired Pectoral Fins
Airplane wings, provide lift
Predominant dorsal fin
Balance

9. Shark’s SEVEN Senses S – Sound O – Olfaction L – Lateral Line
Can hear a fish 100 yards away
O – Olfaction
In one nostril and out the other
L – Lateral Line
V – Vision
E – Electroreception
T – Touch
T - Taste

10. Electroreception Similar to a metal detector Ampullae of Lorenzini
Detects the magnetic field around living organisms
Only other animals with this sense: duck billed platypus and spiny anteater

12. Sharks in Hawaii Aggressive Species Tiger – 18 ft Galapagos – 10-12 ft
Hammerhead ft
Great White

14. Other Species
Blacktip – 8 ft
Reef Black Tip – 6 ft
Reef White Tip – 6 ft
Sandbar ft

15. Shark Attacks never swim alone
don't swim with open wounds or speared fish
don't swim erratically or make splashing noises
avoid the water at night - sharks hunt at night
avoid murky water - sharks may mistake you for a prey
don't harass or provoke sharks
if you witness fish behaving erratically, leave area
if you encounter a shark, remain calm and slowly leave area

16. Environmental Concerns
Sharks are top predators
“Keystone species” that keep prey populations under control

18. Sharks extinct? Populations continue to decline
If fishing continues, could go extinct
18 species are threatened with extinction

19. Our Impact…

20. Something to Think About…
~ 6 people killed by sharks a year
~ 12 million sharks killed by humans
Bycatch
Fisheries

21. Basic Fish Fin Functions
Dorsal fin - stability in swimming
Pelvic fin - stability in swimming
Caudal fin - main propelling fin
Anal fin - stability in swimming
Pectoral fins - Locomotion and side to side/ back forth movement.