1. Chordates

2. What is a Chordate? Hollow nerve cord
Notochord: long supporting rod below nerve cord
Pharyngeal pouches: gills
Tail

3. Muscle segments
Tail
Anus
Pharyngeal pouches
Mouth
Hollow nerve cord
Notochord

4. Nonvertebrate Chordates
Tunicates
Filter-feeders
No notochord or tail
Lancelets
Exchange gas through their skin
Closed circulatory system: no true heart

5. Fishes Aquatic vertebrates Fins: movement Scales: protection
Gills: gas exchange
Evolution of jaws and fins were important developments in fish

6. Form and Function Feeding: every mode Circulation: 2 chamber heart
Excretion: release ammonia
Chemoreceptors: taste and smell
Lateral line system: detect gentle currents and vibrations
Swim bladder: buoyancy

7. Jawless Fish No true teeth or jaws Skeletons: fibers and cartilage
Keep notochords as adults
Lampreys: parasites on fish, whales, & dolphins
Hagfishes
Light detecting sensors
Feed on dead & dying fish
Secrete slime
Have six hearts

8. Cartilaginous Fish Sharks, rays, skates Skeleton: cartilage
Toothlike scales
1,000’s teeth

9. Bony Fish Skeletons: bone Ray-finned fish
Fins: bony spines connected a thin layer of skin
Lobe-finned fish
Fleshy fins support bones
Some bones are jointed