2. FISH Osteichthy Bony fish 20,000 species Big →Little species All aquatic habitats Cold blooded Scales and mucus Gills Chondrichthy Cartilage fish 1,000 species Same

3. Hydrolagus collei Chimaera

7. Fish Osteichthy Cannot close eye External Fertilization External Development Chondrichthy Some have eyelids INTERNAL fertilization Development SOMETIMES External

8. Fish Osteichthy Caudal Fin = Homocercal Swim Bladder = YES Neutrally Buoyant 1 Row of teeth Teeth permanent Scales grow back Chondrichthy Caudal Fin = HETEROcercal Swim Bladder = NO Negatively Buoyant Many rows of teeth Teeth replaceable Scales do NOT grow back

9. Battle against Negative Buoyancy Cartilage is lighter than Bone (negatively buoyant but LESS sinking). Body shape helps give them “lift”. Caudal fin Heterocercal

10. Battle against Negative Buoyancy #1 Caudal fin Heterocercal #2 Pectoral fins like?????

11. Battle against Negative Buoyancy #1 Caudal fin Heterocercal #2 Pectoral fins like?????

12. Battle against Negative Buoyancy #1 Caudal fin Heterocercal #2 Pectoral fins like Airplane wings #3 Liver is 25% of body weight

13. Battle against Negative Buoyancy SO…. Cartilage is lighter than Bone + Caudal fin Heterocercal + Pectoral fins like Airplane wings + Liver is 25% of body weight = Neutral Buoyancy?????

14. Chondrichthys are NEGATIVELY BUOYANT

16. Carcharias taurus

18. Hearing 0.5 miles away. (10 football fields) Hear struggling animals. Better than humans

19. Smell 1 drop in 25 gallons or 1 ppm. Openings to nose can locate exact direction of scent. Better than humans

21. Lateral Line Allows them to “feel” movements. Better than humans

23. Vision Eyes very important. Some sharks can cover their eyes while attacking food, with a Nictitating Membrane. Great white shark can roll eye back into head for protection. Sharks vision 10X better than a cat in darkness. Better than humans

27. Ampullae of Lorenzini Detect electromagnetic impulses. Living organisms give off electromagnetic signals. Heart beating, muscle twitching, etc Better than humans

30. SEX

31. Chondrichthyes Internal Fertilization

36. Courtship (may the best male win!)

39. Chondrichthyes Development ( a bit more tricky!) 3 different ways:

40. Oviparous Shark lays eggs in the water and leaves. No parental care. No added parental nourishment or protection.

42. Viviparous Female gives birth to live young. Baby sharks are attached to mother by placenta (nourishment) Advantage—greater protection (pre-birth) If babies are larger, then less babies.

45. Ovoviviparous Babies are in egg cases, but eggs are carried by mother. No added nourishment given. Advantage: added protection from external eggs.

48. Carcharias taurus

49. (Survival of the Fittest) Intrauterine Cannabilism Or Oophagy

51. SHARK ATTACKS 450 species total 447 chocolate labs 3 pit bulls

59. Annually, between 100 Million and 200 Million sharks are killed worldwide just for their Fins.