2. Fishes

3. What is a chordate? At some point in life, they have: –Notocord –Dorsal hollow nerve cord –Post-anal tail –Pharyngeal slits At some point in life, they have: –Notocord –Dorsal hollow nerve cord –Post-anal tail –Pharyngeal slits

4. Invertebrate Chordates? Protochodates –Lancelets and tunicates –Have all other characteristics but no vertebrae Protochodates –Lancelets and tunicates –Have all other characteristics but no vertebrae

5. Fishes First and most abundant vertebrates Evolve about 500 MYA Minimum 30000 species (half of all verts) Major groups: –Jawless (Agnatha) –Cartilaginous (Chondrichthyes) –Bony (Osteichthyes) First and most abundant vertebrates Evolve about 500 MYA Minimum 30000 species (half of all verts) Major groups: –Jawless (Agnatha) –Cartilaginous (Chondrichthyes) –Bony (Osteichthyes)

6. Agnatha Jawless fishes Lack true vertebrae Hagfish and lampreys http://www.youtube.com/watch?v= NYRr_MrjebAhttp://www.youtube.com/watch?v= NYRr_MrjebA Jawless fishes Lack true vertebrae Hagfish and lampreys http://www.youtube.com/watch?v= NYRr_MrjebAhttp://www.youtube.com/watch?v= NYRr_MrjebA

7. Chondrichthyes Cartilaginous fishes Sharks, rays, skates and ratfish Cartilaginous fishes Sharks, rays, skates and ratfish

8. Characteristics Cartilaginous skeleton Ventral mouth with moveable jaws Paired lateral fins Rough skin (Placoid scales) Cartilaginous skeleton Ventral mouth with moveable jaws Paired lateral fins Rough skin (Placoid scales)

10. 

11. Sharks

19. http://www.youtube. com/watch?v=uQrB wN39LJI

20. Are Sharks Dangerous? http://www.flmnh.ufl.edu/fish/sharks/statistics/GAttack/World.htm

21. Are Sharks Dangerous?

22. Who’s number one?? 1.Great White 2.Tiger 3.Bull Others: Sand Tiger, Hammerhead, Shortfin Mako 1.Great White 2.Tiger 3.Bull Others: Sand Tiger, Hammerhead, Shortfin Mako

23. Why do sharks attack?

24. Other explanations?

26. Fear the... Deer?? Animal Fatalities (avg/yr) –Deer = 130 (vehicular) –Dogs = 18 –Snakes = 15 –Mountain lions = 0.6 –Sharks = 0.4 (statistics from International Shark Attack File) Animal Fatalities (avg/yr) –Deer = 130 (vehicular) –Dogs = 18 –Snakes = 15 –Mountain lions = 0.6 –Sharks = 0.4 (statistics from International Shark Attack File)

27. Who is the bigger threat?

28. Rays and Skates

29. Characteristics Dorsoventrally flattened Ventral gill slits Expanded pectoral fins Few scales Small or plate-like teeth Dorsoventrally flattened Ventral gill slits Expanded pectoral fins Few scales Small or plate-like teeth

30. What’s the difference? Rays –Viviparous –Whip-like tail with stinging spine Rays –Viviparous –Whip-like tail with stinging spine Skates –Oviparous –Broader tail with apparent dorsal fins Skates –Oviparous –Broader tail with apparent dorsal fins

32. Ratfish (Chimaeras) Mostly deep water Prey on crustaceans and mollusks Mostly deep water Prey on crustaceans and mollusks

33. Bony Fishes (Osteichthyes) 96% of fishes Fresh and saltwater 96% of fishes Fresh and saltwater

45. Sensory/Nervous System CNS - Brain w/ spinal cord Olfactory sacs Complex moveable eyes (adjust position to focus) Lateral line Ampullae of Lorenzini Inner ears - hearing and equilibrium CNS - Brain w/ spinal cord Olfactory sacs Complex moveable eyes (adjust position to focus) Lateral line Ampullae of Lorenzini Inner ears - hearing and equilibrium

47. Territoriality Some establish permanent homes More common with crowding (ex. Reefs) Agonistic encounters Some establish permanent homes More common with crowding (ex. Reefs) Agonistic encounters

48. Schooling Coordination maintained by vision, lateral line, olfaction, etc. Advantages? Disadvantages? Coordination maintained by vision, lateral line, olfaction, etc. Advantages? Disadvantages?

49. Migration Periodic mass movements Daily, yearly, once in a lifetime Vertical or horizontal Why migrate? Guidance? Anadromous vs. Catadromous Periodic mass movements Daily, yearly, once in a lifetime Vertical or horizontal Why migrate? Guidance? Anadromous vs. Catadromous

50. Reproduction/Development Internal vs. external fertilization Male, female or both? Courtship behavior Oviparous, ovoviviparous, viviparous Larval metamorphosis Internal vs. external fertilization Male, female or both? Courtship behavior Oviparous, ovoviviparous, viviparous Larval metamorphosis