1. Fish
Gill breathing, ectothermic, aquatic vertebrate that has fins, skin covered in scales.

2. Classes of fish Myxini – Hagfishes Cephalaspidomorphi- Lampreys
Chondrichthyes- Cartilaginous fish
(sharks-rays)

3. 2 classes of bony fish
Actinopterygii – ray finned fishes – 23,000 species
Sarcopterygii – lobe finned fishes(fleshy) – 8 species (coelacanth)

4. Modes or reproduction Oviparous – egg layed
Ovoviviparous-Developing young stay in oviduct and are nourished by yolk sac
Viviparous- true live bearing – nourished by placenta

5. Myxini Hagfish Scavengers 43 species Almost blind Keen sense of smell
Hooks onto prey two toothed plates

6. Myxini Eel like body Slime glands(milky white) No fins
Caudal fin along dorsal surface
Cartilaginous
Smooth skin(naked)
No stomach
No cerebellum
Fluids same as seawater
No larval stage
Possess both sex organs only one functional

7. Cephalaspidomorphi Lamprey mouth Holds rocks to anchor
Parasitic and predaceous

8. Cephalaspidomorphi Sexes separate Single gonad Sucker mouth
Well developed teeth
17 species found in North America
Also found Eurasia
Breed in freshwater
Anadromos – swim up river

9. Cephalaspidomorphi Lampreys attached Eel like Naked skin
Regulated body fluids
No stomach
Well developed eyes

10. Chondrichthyes
Sharks
Rays
Skates
850 living species

11. Chondrichthyes Rays Specialized for life on the sea floor Skates
Electric rays
Sting rays
Bat rays

12. Chondrichthyes Rays Gill openings on underside of head
Spiracles on top
Water taken in through the spiracles

13. Chondrichthyes
Many sharks don’t survive in captivity or they act very different in aquariums
So many species of sharks are still not well researched

14. Chondrichthyes Pelvic fins in male modified to form claspers
Fusiform body(spindle)
Two olfactory sacs
Endoskeleton entirely made up of cartilage
Five to seven sets of gills
No swim bladder or lung
Keen sense of smell
Lateral line
Electroreception
Moderate vision

15. Chondrichthyes Separate sexes Internal fertilization Oviparous
Ovoviviparous
viviparous
25 freshwater
2nd largest vertebrates
Heterocercal tail-turns up

16. Sarcopterygii- fleshy finned

17. Actinopterygii
Bony fish

18. rockfish

19. Osteichthyes - Actinopterygii
Perch

20. Osteichthyes- Actinopterygii
Clownfish

21. Osteichthyes
Seahorse

22. Osteichthyes
Seahorse

23. Osteichthyes
Piranha

24. Osteichthyes

25. Osteichthyes 410 million yrs ago
Most numerous and diverse group of vertebrates
Diverse body form
Specialized jaws
Capable of osmotic regulation
Separate sexes
External fertilization

26. Respiratory Functions (Exchange of Gases)
Mouth-Take in oxygen(water) and food
Operculum-(Protects gills)-Opens and closes to help oxygen move over the gills-increases efficiency

27. Water enters mouth travels to pharynx(throat)and passes over gills
The outward motion of the Operculum creates a negative pressure increasing volume of water over gills

28. Early fish The first fishes had a lack of paired fins and no jaws
Decreased mobility and sources of food
Development of jaws expanded food sources available
Carnivores /herbivores etc.

29. Locomotion Functions (Movement to Keep Upright)
Pectoral Fins and Pelvic Fins-Used for steering, slow swimming and to keep the fish upright
Dorsal and Anal Fin-Used for stability
Caudal Fin-Used for movement and fast swimming

30. Pectoral fin – front legs
Pelvic fin – hind legs

31. Protective Functions Skin Pigment-Provides camouflage
Scales-Protects the skin, parasites, easier swimming

32. Sensory Functions (Transfer Stimuli to Nerve Impulses)
Nostrils-Lets chemicals into the nostril cavity (smell, olfactory bulbs)
Eyes-Large pupils let more light in to help seeing
Lateral Line-Connection of nerve endings that carry low frequency vibrations and depth pressure. Depth and solid objects.
Tongue-touch, oxygen movement, food movement

33. Anadromous- lives at sea return to fresh to spawn - salmon
Catadromous- lives in fresh water return to sea to spawn- eels
Homing instinct regulated by smell of parent stream
Position of sun gets them to the river mouth
From ocean

34. Internal Anatomy Respiratory-gases between blood and oxygen
Gill-Oxygen passes over the gills, O2 is absorbed through the membranes of the Filaments by diffusion.

35. Countercurrent blood flow
Blood circulation is opposite water flow
Allows for maximum efficiency of oxygen absorption
85%
Some fish need to keep moving

36. Circulatory Functions-O2, Nutrients, Remove wastes
Heart-2 chambered-Pumps only deoxygenated blood
Spleen-Removes old blood cells

37. Deoxygenated blood goes through heart to gills then to body of fish to deliver oxygen

38. Closed system – separate oxygenated and deoxygenated blood
Single pump/single loop

39. Locomotion
Air/Swim Bladder-Adjusts float level by changing density of gases
Ears-helps to maintain balance and equilibrium

40. Weberian ossicles are small bones that transmit sound vibrations from swim bladder to the inner ear.
Hearing of faint sounds improved
catfish

41. Digestive Functions-Absorption of Food into the Blood
Teeth-used to bite and hold food
Esophagus-used to carry food to the stomach
Intestine-digestion of food and absorption of the food
Stomach-digestion and storing of food
Pyloric Caeca-secretes digestive enzymes
Liver-makes bile to aid in digestion
Gall Bladder-digests fats

42. Excretory Functions-Removal of Metabolic wastes from body
Kidney and gills-removes nitrogen from blood

43. Solid wastes removed through anus