1. Fish

2. Vertebrates (Subphylum Vertebrata)
Backbone enclosing a nerve cord, or spinal cord
Phylum Chordata
Notochord
Pharyngeal pouches
Postanal tail
Dorsal Nerve Chord

3. Phylum Chordata Subphylum Vertebrata
Class Agnatha, Jawless fishes, (Hagfishes and Lampreys)
Class Chondrichthyes, Cartilaginous fishes, (Sharks, Sharks and Rays, Ratfishes)
Class Osteichthyes, Bony fishes

4. Fig. 8.1

5. Tab. 8.1

6. Class Agnatha: Jawless Fishes
Hagfishes and lampreys
lack jaws, most primitive of living fishes
Feed by suction
Lack paired fins and scales
Hagfish (slime eels)
Lampreys, freshwater

7. Class Chondrichthyes: Cartilaginous Fishes
Sharks, rays, skates, and ratfishes
Endoskeleton of cartilage
Paired fins, movable jaws, gill slits
Rough sandpaper – like skin
placoid scales
pointed tip that is directed backward
same composition as teeth

8. Fig. 8.3

9. Class Osteichthyes: Bony Fish
Largest group of living vertebrates
Gills covered by operculum
Usually swim bladder
Highly maneuverable fins
Cycloid scales

10. Biology of Fishes Body Shape Directly related to its lifestyle
Predator or prey
Streamlined, flattened, elongated, etc
Used for camouflage

11. Fig. 8.4

12. Coloration Locomotion Feeding Biology of Fishes Chromatophores
Swim using a sideways movement of the body and tail
Pectoral fins and tail
Aid sharks with buoyancy
Aid bony fish maneuver/swim
Feeding
Carnivorous, herbivorous, filter feeders

13. Fig. 8.11

14. Fig. 8.10

15. Fig. 8.12

16. Digestion Respiratory System Same set up as all vertebrates
Obtain oxygen filtered from the water
Cartilaginous Fish
First pair of gill slits modified into spiracles (pull water in)
Gill filaments, fleshy projections
Lamellae, increase surface area
Diffusion, countercurrent system of flow

17. ;
Fig. 8.6
Counter – current flow

18. Regulation of Internal Environment
Marine fishes keep a constant internal environment
Kidneys, gills, “drinking” water, rectal gland
Cartilaginous fishes increase their solute concentration in their blood
Urea
Created by breaking down proteins.

19. Single – loop Blood Circulation
Simple chamber – pump heart
Blood collects in atrium and leaves through ventricle
In from body out to the gills

20. Nervous System and Sensory Organs
Central Nervous System
Olfactory sacs, sense of smell, opens to nares
Taste buds
Barbels
Nictitating membrane
Lateral line, detect vibrations in the water (neuromasts)

21. Behavior Biology of Fishes Territoriality Schooling Migration
Anadromous, fishes spend most of their lives in the sea but migrate to fresh water to breed
Catadromous, fishes spend most of their lives in fresh water but migrate to salt water to breed

22. Reproduction and Life History
Urogenital Opening
sperm or eggs
Hermaphrodites
Courtship
Internal fertilization
Copulation
Males cartiliginous fishes have claspers
External fertilization

23. Oviparous Ovoviviparous Viviparous Parthenogenesis Biology of Fishes
Spawn eggs
Ovoviviparous
Eggs are retained in reproductive tract
Viviparous
Live – bearers, nutrition comes from reproductive tract
Parthenogenesis
Development of an egg without fertilization

24. Fig. 8.30

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