1. Introduction to Fish

2. fish Phylum Chordata Subphylum Vertebrata Class Agnatha
Class Chondrichthyes
Class Osteichthyes
Class Amphibia
Class Reptilia
Class Aves
Class Mammalia
fish

3. Class Agnatha
- jawless fish: hagfish and lampreys
absence of jaws
no paired fins
cartilaginous skeleton
2-chambered heart

4. Agnatha

5. Jaws evolved from gill supports.
Jaws developed from gill arches located around the pharynx.
cranium
mouth
gill arches
Jaws gave vertebrates a huge advantage as predators.

6. Only two groups of jawed fish still exist.
Cartilaginous fish and bony fish are still in existence.
Cartilaginous fish have skeletons made of cartilage.

7. Cartilaginous fish include the Holocephali and Elasmobranchs
Holocephali include ratfish, a small group of deep-sea fish.
Elasmobranchs include sharks, rays, and skates.

8. Class Chondrichthyes
- cartilaginous fish: sharks and rays
cartilaginous skeleton
2-chambered heart
5+ pharyngeal slits
well developed lower jaw
bony teeth
placoid (tooth-like) scales
ventral mouth and nostrils
nostrils do not open into mouth

9. Cartilaginous fish

10. Chondrichthyes

11. Bronze whaler

12. Eagle ray

15. Chondrichthyes

16. Class Osteichthyes
- bony fish
ossified skeleton
2-chambered heart
pharyngeal slits covered by single bony operculum (gill cover)
membranous fins strengthened with rays
presence of a swim bladder (teleost)
lateral line sensory receptor

17. Bony fish

19. Swim bladder

22. Fish are vertebrates with gills and paired fins.
Fish use specialized organs called gills to breathe underwater.
sheets of thick, frilly tissue filled with capillaries
take in dissolved oxygen from water, release carbon dioxide
water
flow

23. Countercurrent flow is the opposite movement of water against the flow of blood in the fish’s gills.

24. Circulatory system of fish

25. Bony fish have skeletons made of bone.
operculum protects a bony fish’s gills
movements of operculum help bony fish move water over gills

26. Fins are surfaces that project from a fish’s body.
keep fish stable
redirect water around fish as it swims
help fish maneuver in water
dorsal fin
caudal fin
anal fin
pectoral fin
pelvic fin

28. Myomeres – bands of muscle along sides of
Myomeres – bands of muscle along sides of body contract pushing against water, forces body forward

30. Dorsal & anal fins – act as rudders to steer & provide
Dorsal & anal fins – act as rudders to steer & provide stability (unpaired)
Pelvic fins – to turn, balance, & “brake” (paired)
Pectoral fins – steering (paired)

35. Fish senses

36. All fish have a lateral line system.
sensory system
sensitive to small changes in water movement
lateral line

37. Lateral line system

38. Fish scales
Reduce drag and direct water flow

39. Types of fish scales

40. General Life Style Categories
Fish Adaptations and Life Styles
General Life Style Categories
a. pelagic cruisers
occurring in water column far away from the bottom (benthic) environment
often referred to as "blue water"
includes tuna, billfish, blue sharks, mackerel sharks (great whites and mako sharks)

41. b. demersal
bottom-associated fishes, but not usually sitting on the bottom
rely on the benthic environment as a source of food, place to reproduce, and/or place of refuge, etc.
includes most reef fishes (e.g., butterfly fishes, surgeon fishes, wrasses, parrot fishes, etc.)

42. c. benthic
bottom-dwelling fishes that spend the majority of time sitting on the bottom
includes flatfishes, lizard fishes, many scorpion fishes, many hawkfishes, gobies, etc.

43. Body shape
tuna
1) fusiform a) = torpedo-shaped b) allows minimal drag while swimming c) best shape for a pelagic cruise

45. 2) compressed
laterally flattened (e.g., butterflyfishes & surgeonfishes)
allows for maneuverability in surge environments
useful for demersal fishes that hover above the reef
exception seen in flatfishes that lie on one side of the body as benthic fishes

46. John Dory: predator in waiting…

48. 3) elongated or attenuated
long body (e.g., trumpetfish, cornetfish, eels)
seen in demersal fish that either hover motionless in the water)
seen also in benthic fishes (e.g., eels) that hide in holes in the reef

49. 4) depressed
dorso-ventrally flattened (e.g., frogfishes, scorpionfishes & gobies)
broad ventral surface facilitates resting on the bottom
seen in many benthic fishes

50. Body Coloration 1) source of color
pigment color - chromatophores for yellows, reds, oranges, browns, & blacks
structural color - iridophores (reflection) & light refraction for blues, silvers, & rainbows

51. 2) patterns
a) countershading
dark blue or black dorsally, white or silvery ventrally
results in blue water "camouflage“
observed most frequently in pelagic cruisers

52. b) camouflage
matching the background coloration
usually involves having irregular dark blotches and spots
typically seen in benthic fishes, especially benthic ambush predators (e.g., frogfishes, gobies, & many scorpionfishes)
some fishes (e.g., flatfishes) may exhibit rapid color changes in response to different backgrounds

53. Cryptic colouration

54. 5) matching downwelling light
b) camouflage
5) matching downwelling light
Hatchet fish
Cookie cutter shark

55. c) disruptive coloration
1) color pattern breaks up the silhouette of the fish
2) may involve dark bars across the eye and tail region
3) seen in many demersal fishes such as butterfly fishes

56. d) bars and stripes
1) bars are vertical (e.g., manini)
2) stripes are horizontal (e.g., ta'ape)
3) seen frequently in schooling demersal fishes
4) may confuse potential predators by making it difficult to select individual
prey from the school

57. e) misdirection
1) false eye spots, etc.
2) observed in many demersal butterfly fishes

58. f) advertising coloration 1) bright, obvious color patterns
2) possible functions
a) advertising a cleaning station (e.g., cleaner wrasses)
b) advertising a warning (e.g., nohu)
c) advertising for mates (e.g., male parrotfishes)
Hawaiian cleaner
wrasse
Nohu

59. 1) imitating other creatures
g) mimicry
1) imitating other creatures
2) seen in a few demersal and benthic fishes
3) examples
a) blenny (Aspidontus taeniatus) mimics
cleaner wrasses
b) shortnose wrasse mimics Potter's angel which sports a defensive spine

60. g) mimicry
4) leafy sea dragon (Australia)
                                     

61. h) uniform red coloration
most often observed in deep-dwelling or night active demersal fishes
examples include opakapaka, oweoweo, menpachi, & squirrelfishes

62. i) noctural versus diurnal color changes
j) male versus female color differences
k) juvenile versus adult color differences
Dragon wrasse
Stoplight parrotfish
Bluehead wrasse

63. Sex and social behaviour

65. Territoriality
Black angel fish

66. Distribution - Anatomy - Circulation - Respiration
Chondrichthyes (370)
Placoderm
( )
Ostracoderm (510-=350 mybp)
                                                        
                                                           
(360)
Osteichthyes (395)
allows. Class Agnatha or Cephalaspidomorphi, the jawless fishes Subclass (or order) Cyclostomata, the lampreys and hagfishes. (In certain classifications, the lampreys and hagfishes are each considered separate superclasses: Cephalaspidomorphi and Pteraspidomorphi, respectively.) Class Chondrichthyes, the cartilaginous-skeleton fishes Subclass Holocephali, the chimaeras, or ratfishes Subclass Elasmobranchii, the sharks, skates, and rays Class Osteichthyes, the bony fishes Subclass (or order) Crossopterygii, the coelacanth Subclass (or order) Dipnoi or Dipneusti, the lungfishes (In some classifications, the above two subclasses are treated as orders of a single subclass, the Choanichthyes or Sarcopterygii, the lobe-finned fishes.) Subclass Actinopterygii, the ray-finned fishes Infraclass (or superorder) Chondrostei, the primitive ray-finned bony fishes: sturgeons, paddlefish, and bichirs (In some classifications, the bichirs are placed in a subclass of their own, the Brachiopterygii.) Infraclass (or superorder) Holostei or Neopterygii, the intermediate ray-finned fishes: gars and the bowfin (In certain classifications, the gars are treated as a separate superorder, the Ginglymodi. The term Ginglymodi also has been used to designate the gars as an order, but this term has been replaced at the ordinal level by the term Lepisosteiformes; orders are now indicated by the ending -formes.) Infraclass (or superorder) Teleostei or Neopterygii, the advanced bony fishes: herring, salmon, perch.
Distribution - Anatomy - Circulation - Respiration
lamprey
& hagfish

68. Coelacanth

70. Lungfish

71. New Zealand Fish
Over 1,000 species, many in Indo-Pacific and Australia as well
Of the 270 coastal species, approx. 25% are endemic

72. Triplefins
Osteichthyes

73. Parore: Herbiverous fish feeding on kelps and other algae

74. Demersal fish live on the sea floor

75. Pelagic fish live in the water column above

76. Variations on a theme

78. Osteichthyes

80. Blue maomao : plankton feeders

81. Trevalley : plankton feeders

82. Snapper

83. Leatherjacket

84. Yellow-finned tuna