1. Fish

2. History First vertebrates
500 m.y.a.
Fish are the most economically important marine organism
Fertilizer, feed, protein

3. Classification Kingdom- Animalia Phylum- Chordata
Sub Phylum- Vertebrata (backbone)
Classes-
Agnatha
Chondrichthyes
Osteichthyes

4. Vertebrates Four fundamental characteristics
Backbone (vertebrae/spine)
Nerve cord (spinal cord)
Protected by vertebrae
Skull
Bilateral symmetry

5. Classification Kingdom- Animalia Phylum- Chordata
Sub Phylum- Vertebrata (backbone)
Classes-
Agnatha – jawless fishes
Chondrichthyes – cartilaginous fishes
Osteichthyes – bony fishes

6. Agnatha
Jawless fish: Lampreys, Hagfish

7. AGNATHANS Jawless fish - agnatha Oldest group – very primitive
Scale-less skin
Some Parasitic / some filter feed
Circular mouth with fleshy teeth
Cartilaginous skeleton

8. Types of Agnathans Hagfish - Scavengers, not much known about them.
Lamprey- fresh and salt water; parasitic and prey on other fish.
* Both have cartilaginous skeletons and sucker-like mouths.

9. Chondrichthyes
Cartilaginous Fish: Shark, Ray, Skate, Chimaera

10. CHONDRICHTHYES cartilaginous fish condrichthyes
Skeleton made of cartilage
Sharks, rays, skates
All are predatory except 4 species!

11. The 4 exceptions are filter feeders
Whale sharks – warm shallow water
THE LARGEST FISH IN THE SEA!!!

12. The 4 exceptions are filter feeders
Basking sharks – cold shallow water
THE SECOND LARGEST FISH IN THE SEA!!!

13. The 4 exceptions are filter feeders
megamouth shark – cold deep water

14. The 4 exceptions are filter feeders
manta ray– shallow warm water

15. Chondrichthyes Sharks adapted for a predatory lifestyle.
Hydrodynamic body (fusiform)
Stiff pectoral fins (speed).
Have live births.
Placoid scales.
Mantas, Sting Rays
live in shallow water, have mouths located on the underside, fairly docile, wide flat bodies and wing-like fins that are flexible.

16. Types of Chondrichthyes
Sharks and Rays
No operculum and must keep moving to breathe.
Placoid scales that feel and look more like sandpaper.
Skeletons made of cartilage not bone.

17. Types of Chondrichthyes
Chimaeras
No operculum and must keep moving to breathe.
Scaleless
Bottom feeders
Longnose chimaera has a venomous spine

18. Chondrichthyes - SHARKS
Fusiform body shape
Caudal fin = heterocercal
2 dorsal fins
Paired pectoral fins
‘conveyor belt’ teeth
Cartilaginous skeleton

20. Chondrichthyes - SHARKS
SPECIALIZED BODY PARTS
Extra oily liver for buoyancy
Lateral line
Ampullae of lorenzini
Keen olfactory & optical senses

21. They get a Bad Rap :-(
Watch “Planet in Peril: Battle Lines”

22. Species

23. Osteichthyes Bony Fish: Salmon, Carp, Tuna
Over 20,000 different species

24. Types of Osteichthyes Ray Finned: Lobe Finned: Most fish
Fins are supported by bony structures called Rays.
Teleosts are the most advanced (homeocercal tails and mobile fins).
Lobe Finned:
Fins are long, fleshy, muscular, supported by central core of bones.
possible ancestors of amphibians.
Examples are: Coelacanth, Lungfish

25. Fish Characteristics Gills Backbone Paired Fins
Single Loop Circulation
Two chambered heart

26. Fish Anatomy

27. Fins

28. Different Dorsal Fins

29. Fish Respiration Water flows over gills as fish opens mouth and swims.
Water flows opposite direction of blood flow.
O2 diffuses from the water into the blood.
Gills are made of thousands of gill filaments.
Gills are covered by the Operculum.

30. Up Close and Personal

31. Fish Circulation Fish heart has 2 chambers Single loop circulation
Blood flows into gills, picks up O2, goes to the body, returns to the heart.

32. Fish Reproduction
Most Fish reproduce sexually, and fertilize their eggs externally (Sharks-internally).
Spawning is the process of fertilizing eggs.
Baby fish are called FRY.

33. Fish Adaptations
Lateral Line System- used to detect vibrations, orient the fish in water, it is a line of cells running down the side of the fish.
Operculum- gill cover, movement of operculum allows more water to be drawn in.
Swim Bladder- a gas filled sac that helps the fish maintain buoyancy. Sharks don’t have a swim bladder!
Fins- Dorsal, Caudal, Pectoral, Pelvic, Anal.

34. Adaptations
Air Bladder Operculum Lateral
Gills Line
Fins

35. Body forms of fishes 1. fusiform Sharks, tuna, bluefish
Streamlined, torpedo shaped
Fast long distance swimmers
Open water predators

36. Body forms of fishes 2. compressed Perch, butterfly fish, angelfish
Flattened laterally
Quick bursts of speed - short distance
Easily move in tight spaces

37. Body forms of fishes 3. depressed Flounder, fluke, stingray
Dorso-ventrally flattened
Live on the bottom
Eyes on top of body

38. Color
Can be an important identifying characteristic when dealing with live specimens. There may be no color in preserved specimens
Color varies with habitat
Color varies between males and females especially during breeding season
Color patterns can be important.
Vertical bars versus Horizontal stripes.

39. Body forms of fishes 4. attenuated Eels, lamprey, pipefish
Elongated, tubular shape
Many Live in holes / burrows
Many secrete heavy mucus

40. Other Morphological Characteristics Mouth Position
Mouth position is not only a good identifying characteristic but it also tells you something about what the fish eats and where you would likely find it in the water column.
Taken from: Helfman et. al. 1997, The Diversity of Fishes

41. Other Characteristics
Morphometrics and Meristics
Morphometrics are things you can measure
length of snout, eye diameter.
Meristics are things you can count
number of anal fin rays, scales above the lateral line

42. Body parts of fish
Get ready to draw a fish!!!

43. 1. Caudal fin - tail fin
Used for forward motion and acceleration

44. Singular fins
2. Dorsal fin & Anal fin
Used to prevent rolling/tipping

45. 4. pectoral fin & 5. pelvic fin
paired fins (left & right)
4. pectoral fin & pelvic fin
Used to balance, stop & turn

46. 6. Spines
Used for protection
Some contain poison sacs

47. 7. operculum
Covers & protects gills
Not found in sharks

48. 8. Lateral line
Sensory canals used to detect changes in water pressure around the fish (similar to human ear)

49. Lateral Line and schooling

50. COMPARISON OF CARTILAGINOUS & BONY FISHES
TRAIT CARTILAGINOUS BONY_____
TUNA, COD, SALMON,
SHARKS, RAYS, SKATES
EXAMPLES
SKELETON
CARTILAGE
BONE
ABSENT – OILY LIVER PROVIDES BUOYANCY
PRESENT – AIR FILLED FOR BUOYANCY
SWIM BLADDER

51. COMPARISON OF CARTILAGINOUS & BONY FISHES
TRAIT CARTILAGINOUS BONY_____
EXTERNAL – LAY MILLIONS OF SMALL EGGS
INTERNAL – HAVE FEW LARGE YOUNG IN LIFE TIME
FERTILIZATION
SCALES
PLACOID – SPINY EMBEDDED IN SKIN
GANOID – PLATELIKE CTENOID & CYCLOID ARE FLAT, FLEXIBLE, OVERLAP

52. COMPARISON OF CARTILAGINOUS & BONY FISHES
TRAIT CARTILAGINOUS BONY_____
HAVE OPERCULUM COVER & PROTECT GILLS
GILLS
NO OPERCULUM HAVE GILLS SLITS
FEEDING BEHAVIOR
ALL PREDATORS FOUR EXCEPTIONS
GREAT VARIATION IN FOOD SOURCES
RIGID AND UNSEGMENTED
Heterocercal tail
FLEXIBLE AND SEGMENTED
Homeocercal tail
FINS
NOT FUSED TO JAW -REPLACEABLE
TEETH
FUSED TO JAW - IRREPLACEABLE