1. Phylum Chordata
Chapter 25 and 26

2. A. Introduction
Most familiar to humans
Share 8 characteristics at some point in development
Notochord
Flexible rod-like structure extending the length of the body
Axis for muscle attachment
Dorsal, Tubular Nerve Cord – usually enlarges to form the brain

4. c. Pharyngeal Gill Slits 1) Perforated slit-like opening that lead from the pharyngeal cavity to the outside 2) May close completely in adults (humans) 3) May turn into gills

5. d. Postanal Tail 1) Structure behind the anus 2) Used for propulsion in water 3) Waggable in most mammals 4) Vestigial structure in humans

6. e. Endostyle or Thyroid Gland 1) Endostyle – secretes mucus that traps small food particles 2) Thyroid - gland which secretes hormones in higher order vertebrates 3) Found in all chordates but no other animal

7. f. Ventral Heart – closed circulatory system with veins and arteries g
f. Ventral Heart – closed circulatory system with veins and arteries g. Complete Developed Digestive System h. Endoskeleton – made of cartilage and bones

8. B. Subphylum Vertebrata
Fish
Most numerous of all vertebrates
Widespread characteristics – size, habitat, shape, color
Adaptations
Water effects body structure
Buoyancy – trap gas in body to regulate vertical position
Paired fins to control movement

9. 4) Mucus covering 5) Gills 6) Lateral line system a) Structure of nerves connected to the brain b) Detects vibrations and chemicals in water

10. 2. Class Agnatha a. Jawless fish b
2. Class Agnatha a. Jawless fish b. Lampreys (freshwater) and hagfish (ocean) c. Circular mouths d. No plates or scales e. Notochord remains throughout their life f. Unpaired fins

11. Hagfish (65 species) Lampreys (40 species) g. Hagfish VS. Lampreys
Hagfish (65 species)
Lampreys (40 species)
Scavengers of dead or dying fish
Usually parasitic – suck body fluids
Live at bottom in cold ocean water
Locate prey by smell
Eat things from inside out or tears chunks off
Attach by suction, tears hole, produces anticoagulant
Slime glands – for predation
No slimes glands
Hide in mud burrows
No stomach
Prize for info about breeding habits

14. 3. Class Chondrichthyes a. Sharks, skates, and rays b
3. Class Chondrichthyes a. Sharks, skates, and rays b. Cartilage skeletons c. Use smell and lateral line to track prey d. Have placoid scales e. Ventral mouth

16. f. Sharks 1) Side to side motion of back fin 2) Pectoral fins – compensate for downward thrust of tail 3) Teeth a) Typically 6 – 20 rows b) When tooth breaks or is worn it is lost and replaced (20,000 teeth throughout life) c) Rounded – crush food like clams d) Triangular teeth w/serration – hook at tear at prey

18. 4) Can sense blood from up to
4) Can sense blood from up to .3 miles away 5) Respiration a) 5 – 7 gill slits (no operculum) b) Buccal pumping or ram ventilation 6) Reproduction a) Eggs internally fertilized b) Males have claspers 7) No swim bladders – must swim to avoid sinking

20. Most Dangerous Sharks – Naked Science, 2013
Attack Rate
Fatality Rate
Great White – 37% of all attacks
28%
Bull Sharks – 15% of all attacks
34%
Tiger Sharks – 11% of all attacks
31%

21. Tonic Immobility

22. 4. Class Osteichthyes a. Operculum over gills 1) Opens as mouth closes allowing incoming water to flow over gills 2) Seals when closed to prevent back flow b. Fins 1) Caudal – tail fin for forward motion 2) Dorsal – top (back) fin for balance – up to 3 3) Anal – bottom by anus for upright balance and moving in straight line – only 1

23. 4) Pelvic – bottom by head for fine tuning movements – paired 5) Pectoral – sides by gills for brakes, balance, steering, “walking” – paired c. Locomotion 1) Thrust through lateral forces 2) Fast fish undulate less - Eel – movement is serpentine = slow - Tuna – body doesn’t flex = 50 mph

24. Mudskipper https://www.youtube.com/watch?v=FLh4ODMBGJE

25. d. Scales 1) Protection and reduce friction when swimming 2) Types a) Ganoid – primitive boney fish – diamonds b) Cycloid – circular c) Ctenoid – square 3) Many times have countershading

27. e. Reproduction 1) Separate sexes with external fertilization 2) Hermaphroditic f. Internal anatomy 1) Swim bladder – expands and compresses with pressure 2) Mouth, pharynx, esophagus, stomach, pyloric ceca, intestine, anus 3) 2 chambered heart

28. g. Feeding 1) Most time and energy spent here 2) Most are carnivores – swallow whole 3) Some are herbivores – relatively uncommon but important link in food web 4) Suspension feeders a) Phytoplankton/zooplankton – strained b) Most abundant of all marine fish c) Important food for carnivores 5) Scavengers

29. Feeding - https://www. youtube. com/watch
Feeding - Snagging -

30. Asian Carp
Filter feeders which can eat up to 20% of their body weight per day.
They can be up to 100 lbs.
No natural predators.
Half million eggs laid each time they spawn.

31. 6) Style a) Packs – piranhas http://www. youtube. com/watch
6) Style a) Packs – piranhas b) Strength – Muskie or Tiger Oscar c) Stealth/trickery – flounder d) Creative – archer fish
Goldeye

32. h. Respiration/Circulation 1) Counter-current flow – water and blood flow in opposite directions 2) Ram ventilation – need to be moving