1. Phylum Chordata

2. Chordate: animals that have a notochord in the embryonic form

3. Notochord: a flexible rod that extends the length of the body

4. 4 Characteristics of Chordates
1. Dorsal nerve cord
2. Notochord
3. Pharyngeal gill slits
4. Tail

5. Subphylum Vertebrata: animals whose dorsal nerve cord is protected by a series of bone

6. 4. Vertebrae that encloses/protects the nerve cord
Characteristics
1. Endoskeleton
3. Hinged Jaw
2. Skull and Backbone
4. Vertebrae that encloses/protects the nerve cord

7. Fish: most primitive vertebrates

8. Ichthyology: study of fish
-first jawed vertebrates -evolved during the Devonian Period (350 MYA) -fins/scaled/gills -two chambered heart with a closed circulatory system

9. Fish Heart
Atrium: a chamber that holds blood before pumping it into the ventricle
Ventricle: muscle chamber responsible for pumping blood throughout the body

10. Fish external anatomy

11. Fish Taxonomy Fish Class Agnatha (jawless) Class Osteichthyes (bony)
Class Chondrichthyes (cartilagenous)

12. Class Agnatha: “no jaws”
-circular mouth with teeth -freshwater parasites -elongated bodies Ex. Lamprey

13. Class Chondrichthyes: sharks and rays
-cartilage skeletons -lack gill cover -detect electric fields from muscle contractions -swim to keep from sinking Ex. Nurse shark, sand skate

14. Class Osteichthyes: bony fish
-ossified (boney) skeleton -operculum: protective gill cover -skin glands that secrete slimy covering Ex. Muskellunge, rainbow trout, chinook salmon, Carp, lake sturgeon,walleye, flathead catfish, longnose gar, smallmouth bass, whitehorse sucker, yellow perch, black crappie, white crappie

15. Class Amphibia: “double life”
Introduction: -linked to water for reproduction -evolved in the Carboniferous period -ecosystem was all wetlands

16. Class Amphibia: “double life”
Characteristics: -aquatic larval stage with gills (tadpoles) -four legs - tetrapods -herbivores as larva; carnivores as adults -respiration with lungs and through skin -external ear drums -three chambered heart

17. Specimens
-grass frog (Rana pipiens) -bull frog -american toad -red-spotted newt -red eyed tree frog -African clawed frog -poison dart frogs

18. Class Reptilia First terrestrial quadriped
Amniotic egg (oviparous reproduction)
-body covered with scales
-breath entirely with lungs
- “3.5” chambered heart

19. Specimens King snake Ball python Reticulated python Water mocassin
Snapping turtle
Map turtle
Leatherback sea turtle
Eastern painted turtle
Anole
American alligator