1. Fish Live in salt, brackish and freshwater Cold Blooded – body temp matches surroundings

2. Advantages Fins - Paired fins increased stability and maneuverability in water

3. Jaws Jaws allowed fish to seize and manipulate prey

4. Characteristics Internal Skeleton Most breathe with gills Lateral line Swim bladder 2 chambered heart Mucus covered scales

5. Respiration Fish use gills for gas exchange Countercurrent flow - water flows across the gill filaments in a direction opposite to blood flow.

7. Lateral Line A system of canals in the skin that allow fish to sense vibration in the water also have fluid-filled inner ears for hearing

9. Some fish (cartilaginous) also have sensory organs known as “Ampullae of Lorenzini” that can detect weak electrical signals Can locate prey by detecting their muscle contractions

10. Swim Bladder Used to control their position in the water (can stay at one depth).

11. Spiny Pufferfish swim bladder

12. Circulatory System 2 chambered heart – pumps blood to the gills to pick up oxygen

13. Scales Head to tail (reduce drag) Grow rings every year Tell fish’s age

14. Scales Secrete mucus to reduce friction as they swim, and to reduce the risk of infections. Protected by the “operculum”

15. Operculum

16. Countershading - a type of camouflage in which the dorsal (top) side is darker than the ventral (bottom) side.

17. Chemoreception The ability to detect chemicals in the environment – Include smell & taste – Most fish have a well developed sense of smell

18. 3 Classes of Fish Agnatha Chondrichthyes Osteichthyes

19. Agnatha (no jaw) Lamprey and Hagfish Absence of jaws. – Circular toothed mouth to bore into the side of a fish and suck the blood.

20. Lamprey are parasites

21. Hagfish Hagfish are scavengers

22. Agnatha Skeleton made of cartilage. Eel-like body Soft skin/no scales Oviparous (egg laying) – External fertilization

23. Chondrichthyes (cartilaginous) Sharks, Rays & Skates – about 1,000 living species.

24. Rays and Skates Flattened kite or triangular shaped bodies with long whiplike tails

25. Giant Manta Ray

26. Skate

27. Sharks Streamlined body and muscular tail

28. Teeth Several rows of triangular teeth Replaced as they are lost

29. Respiration  Pump water by:  Swimming rapidly  Or by expanding and contracting their mouth

30. Body covered with small, triangular placoid scales.

31. Fins Large caudal fin Dorsal section larger than ventral one. Paired fins (pectoral and pelvic), are nonflexible.

33. Sharks lack a swim bladder. – Store large amount of lipids in the liver – Can be 25% of shark’s mass

34. Acute sense of smell Sharks can detect 1 drop of blood in a square mile of water Ectothermic – cold blooded

35. Reproduction Internal fertilization. – Modified pelvic fins called claspers deposit sperm Ovoviviparous - give birth to live young, the eggs develop without any nutrition from the parent

36. Osteichthyes – bony fish Largest class of vertebrates with over 29,000 species (95% of all fish)

37. Bony skeleton Paired fins, or lobed fins Some have sensory whiskers (barbels) – Catfish, bullhead

39. Lobe-finned fish Muscular fins supported by bones. Their "lung" is a modified swim bladder Able to survive dry spells Can drown if kept underwater and not allowed to breathe air!

40. LUNGFISH

41. COELACANTH

42. Ray-finned fish Most bony fish are ray-finned fish, meaning that they have thin, flexible skeletal rays. – Make up half of all living vertebrates

44. External Fertilization (Spawning) – Lay numerous eggs (high mortality) – Some migrate great distances (salmon) – Always return to place where they were hatched (can travel thousands of miles, jump dams etc.)