1. Chordates
An Introduction

2. Kingdom Animalia- All inverts & verts
Phylum Chordata: All have nerve cords subphyla :
A- Urochordata (tunicates aka sea squirts). Only larvae have notochord
B-Cephalochordata (lancelets aka Amphioxus). Retain notochord throughout adulthood, but “muscle- like” for burrowing
C-Vertebrata- Notochord becomes backbone. 7 Classes

3. Concept Map Chordates Section 33-1 have the following key features
Notochord
Dorsal hollow nerve cord
Pharyngeal gill slits/ pouches
Postanal tail
which is
A flexible supporting structure

4. Chordates
Fig. 23.2a

5. Phylum Chordata
Fig. 23.1

6. Phylum Chordata Notochord Gill slits or pharyngeal pouches
Dorsal hollow nerve cord
Postanal tail
Segmented muscles
Deuterostome

7. Fig. 23.p469a

8. Fig. 23.p469b

9. Fig. 23.p472a

10. Fig. 23.p472c

11. Evolutionary Adaptations of Chordates
From filter feeding ancestors to active predators
Mobility
Oxygen capture
Digestion
Circulation
Nervous system

12. Skeletal Changes Skeleton becomes stronger to work with bigger muscles
Allows more rapid movement
Fig. 23.p477

13. Oxygen Capture
Gill slit and muscular pharynx will move more water over gills
More oxygen is extracted from water
Fig. 23.p478a

14. Circulation
Stronger heart to circulate blood faster
Fig. 23.p478a

15. Digestion Digest more food Muscularized gut Digestive glands Liver
Pancreas
Fig. 23.p478a

16. Nervous System More complex for better
Motor control of body to capture food
Sensory detection of the animals environment
Integration centers (brain)
Fig. 23.p478b

17. Brain With Three Parts
Hindbrain
Midbrain
Forebrain
Fig

18. Figure 33–2 A Cladogram of Chordates
Section 33-1
Nonvertebrate chordates
Jawless fishes
Cartilaginous fishes
Bony fishes
Amphibians
Reptiles
Birds
Mammals

19. Chordate Cladogram Mammals Birds Reptiles Amphibians Fishes
Nonvertebrate chordates
Invertebrate ancestor

20. Figure 33–4 Diversity of Chordates
Section 33-1
Nonvertebrate chordates
(4%)
Mammals
(8%)
Birds
(18%)
Fishes
(47%)
Reptiles
(14%)
Amphibians
(9%)

21. Chordate Subphyla Subphylum. Urochordata Subphylum. Cephalochordata
Phylum. Chordata
Subphylum. Urochordata
Subphylum. Cephalochordata
Subphylum. Vertebrata

22. Sea Squirts

23. Subphylum Urochordata
Sea squirts
Gill slits (pharyngeal slits)
Notochord
Only in larva
Adult has tunic- made of cellulose, sessile

25. Fig. 23.5

26. Fig. 23.7

27. Subphylum Cephalochordata
Amphioxus
Notochord length of body
Dorsal hollow nerve cord
Gill slits
Segmented muscles
Maintain all chordate characteristics as adult

28. Amphioxus
Fig. 23.CO

29. Amphioxus

30. Subphylum Vertebrata: All Vertebrates have:
Endoskeleton- backbone
Closed circulatory system
Bilateral symmetry
True coelom
Sexual reproduction- internal or external
Vertebrate Groups- Fish, Amphibians, Reptiles, Birds, and Mammals

31. Homeostasis
Endothermic (warm-blooded)- internal temp. regulation that must be maintained
Ex. Birds & Mammals
Ectothermic (cold-blooded)- external temp. regulation/ regulated by environment
Ex. Nonvertebrate chordates, Fish, Amphibians, Reptiles

32. Temperature Control in Chordates
Section 33-2
Body Temperature (°C)
Environmental Temperature (°C)
98.6 F- avg human temp

33. Animal Group Endo/ectotherm Behavior/structure Fish Ectotherm
How vertebrates maintain their temperature
Animal Group
Endo/ectotherm
Behavior/structure
Fish
Ectotherm
Swim bladder:
Cold/move up
Hot/move down
Amphibian
Cool/go in sun
Hot/go to water
Reptile
Cool/bask
Birds
Endotherm
Cool/fluff feather
Hot/raise wings
Mammals
Sweat, pant, shiver

34. “Jawless” Fish (most primitive):
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Class Agnatha
“Jawless” Fish (most primitive):
Traits:
-Sucker like mouth(no jaws)
-No fins or paired appendages
-Cartilage skeleton w/ notochord
Ex: lamprey & hagfish

35. Class Chondrichthyes-Cartilage Fish
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Class Chondrichthyes-Cartilage Fish
Traits:
Cartilage skeleton; 2 chambered heart
Lateral line system –detect vibrations (movement & sense)
Paired appendages- pectoral and pelvic girdles
Poor eyesight, great olfactory
Carnivorous or scavenger, no swim bladder
Ex: sharks, skates, rays

36. Fish Scales

37. Tails
Bony fish
Sharks and rays
lungfish

38. Fish Tail Cladogram

39. Kingdom Animalia Phylum Chordata Class Osteichthyes- Bony Fish Traits:
Bony skeleton; 2 chambered heart
Lateral line system/movement & sense
Swim bladder-control depth (buoyancy)
Have operculum over gills
Good smell (olfactory) and eyesight
Ex: perch, bass, flounder