1. Chordates and Fish

4. Chordates 45,000 members Must have the following dorsal nerve chord – vertebrae cranium – skull endoskeleton of bone or cartilage

6. 7 CLASSES of VERTEBRAE

7. 1. Mammalia hair, milk young

8. 2. Aves birds : feathers, hollow bones

9. 3. Reptilia dry scaly skin

10. 4. Amphibia permeable skin

11. And 3 that are FISH!

12. 5. Agnatha jawless fish lampreys and hagfish round mouth long eel like bodies gills evolved to… Lamprey video

13. 6. Chondrichthyes (kahn-Drick-theeez) sharks, skates and rays jaws and paired fins cartilage skeleton unique placoid scales

15. 7. Osteichthyes (Ahs-tee-Ich-theeez) bony fish : salmon, bass, etc. jaws skeleton of bone lobe (mud) or ray finned Largest Bony Fish Longest Bony fish

16. Adaptations to live and Survive in Water trap gas = buoyancy Trap in organ called gas bladder/swim bladder regulates depth with O2, CO2 and N2

17. Adaptations… streamline shape

18. Adaptations… muscular tail : Caudal fin

19. Adaptations… paired fins : 2 dorsal and 2 pelvic

20. Adaptations… mucus = less friction Other escape adaptations Puffer fish

21. Adaptations… gills : gas exchange O2 in and CO2 out

22. Adaptations… lateral line system : nerves for sensing vibrations in water

23. Adaptations… Separate sexes internal and external fertilization spawning Fish fighting