Vertebrate Classes All in Chordate Phylum

1. Vertebrate ClassesAll in Chordate Phylum

2. All vertebrates have… • Bilateral symmetry • Fully developed coelom • Closed circulatory system • Endoskeletal spinal cord (vertebrate)

3. Types of Fish Lamprey (jawless) bony fish Shark (cartilage)

4. Lampreys/Hagfish • Lampreys attach to fish-parasites • Have “round mouths”- no scales • Hagfish are Scavengers of dead and dying fish on ocean bottom

5. Sharks, Skates, Rays • Jaws • The shark’s mouth has 6 to 20 rows of backward-pointing teeth • They can detect blood from an injured animal as far as 500 miles away • No swim bladder

6. Bony Fish Most are familiar fishes and include snake-like eels, salmon, trout, bass, herring, and lantern fish (most fish we eat)

7. Fish Fishes are the most numerous of all vertebrates and most widespread in their distribution

9. Obtain Oxygen • Fish obtain O2 through their gills • Fish can extract 85 % of the oxygen passing over the gills • Blood goes to the gills, is oxygenated and sent to all parts of the body • Single loop circulation in fish

10. Fish have a two chambered heart – blood is passed over the gills where it picks up oxygen and gets rid of carbon dioxide.

11. Fish - 2 chamber heart 1 atrium – makes sure blood is always available for ventricle 1 ventricle – pumps blood to gills and then to the body

12. 2 chamber heart Some problems: Slow delivery MUCH more energy required to move on land (or in air) = more O2 needed faster

13. Fish Reproduction Usually external fertilization Large numbers of eggs are fertilized during Spawning – when fish reproduce

14. Salmon Video at National Geographic

15. Barndoor skate (Dipturus laevis) Shark Reproduction Skate Sharks, Skates and Rays fertilization is internal-most are born live Some sharks lay eggs

16. Variety of Rays There are many different types of rays including stingrays, electric rays, butterfly rays, round rays, manta rays, guitarfish, and sawfish.

17. Early aquatic adaptations • Teeth (everyone) – evolved from skin --shift from scavenging (lancelets) to predation (lampreys) • Jaws (sharks and bony fish) --provide chewing / biting force

18. Later aquatic adaptations • Bony fish evolve swim bladder --air bag that allows fish to move up and down in water-called buoyancy --sharks sink when not swimming • Swim bladder adapted to be lungs on land

19. Transitional fish / amphibian? • Tiktaalik roseae

20. Amphibians frog salamander

23. Amphibians on land • Four legs to walk on land-These are adapted fish fins at right angles from body • Ectotherms • Hibernate or Estivate depending on climate

24. 3 Chamber Heart O2 through lungs and moist skin called cutaneous respiration 2 atria – 1 from body (deoxygenated), 1 from lungs (oxygenated) 1 ventricle – pumps blood to lungs and body

25. 3 chamber heart Problem solved: Blood getting to body cells faster (heart pumps directly to body) New problem: Deoxygenated blood mixes with oxygenated blood

26. Amphibian limitations • Must live in warm, wet areas for 2 reasons 1) External fertilization - Reproduce in water (lay eggs there) egg  tadpole  young frog  adult frog 2) Go to water to keep skin moist

27. Bullfrogs Eat Everything

28. Reptiles

29. Reptiles turtle crocodile snake

30. Claws • Strong, bony skeletons and toes with claws • Claws-aid in climbing, digging and movement in various terrains

31. Reptiles further on land • Evolved to live entirely on land 1) Scales to prevent water loss 2) Laying eggs that can survive on land = amniotic egg - Internal fertilization

32. Scales

33. Eggs • Amniotic egg – has all the water and nutrients inside for embryo to survive

34. Chameleon Babies

35. Reptile limitations • Must live in warm areas • Limited by ectothermy

36. Regulating body temperature • Ectotherm (“cold-blooded”) – animal does not maintain a body temperature outside temp = body temp

37. Ectothermy • Become sluggish in very cold temperature • Bask in the sun or seek shade

38. Pros No energy needed to keep warm inside Cons Restricted to warm climates only Active only during day Ectothermy

39. Heart • Ventricle of heart partly divided by a septum • Still incomplete separation of oxygen-rich and oxygen-poor blood • Crocodiles and alligators have a ventricle that is totally separated into two pumping chambers

40. Circulation Double loop circulation

41. Transitional bird / reptile • Archaeopteryx

42. Birds

43. Birds • Most capable of flight • Feathers, wings, hollow bones, no teeth • Amniotic egg like reptiles

44. Birds all over land • Can live in any environment (dry / wet or warm / cold) • To help conserve body heat, birds fluff out there feathers to insulation. • endothermy is crucial adaptation

45. Endothermy • Endotherm (“warm-blooded”) –keeping a constant body temperature Pros • Can be active even in colder biomes • Can be active at night (nocturnal predators) Cons • Requires lots of energy (must find food often)

46. Hummingbirds

47. 4 chamber heart 2 atria – 1 from body (deoxygenated), 1 from lungs (oxygenated) 2 ventricles – 1 pumps to lungs , 1 pumps to body

48. 4 chamber heart • Even more energy needed for cells • Birds = energy for flight • Mammals = energy for large brains • NO mixture of blood in 4 chamber heart

49. Another comparison 3 chamber heart (mixing problem) 4 chamber heart (no mixing problem)

50. Digestive and Excretory system • Food passes from the mouth cavity straight to the esophagus. • Enlargement of the esophagus called the crop stores and moistens food. • Then passes through the gizzard, a muscular organ that kneads and crushes the food