FISH

1
FISH
2
FISH
28,000 species Diverse aquatic lifestyles Are a
grade some became amphibians
3
Smallest 8.4 mm long
Stout Infantfish
4
Largest 13 metres long
Whale Shark
5
FISH INVENTIONS
BONES JAWS GILLS LUNGS FINS INVADING LAND
6
CLASS SPLIT INTO3 GRADES
Jawless c. 90 Cartilaginous
c. 980 Bony gt 27,000
7
CLASS SPLIT INTO3 GRADES
Jaws? Bone? Jawless X
? Cartilaginous ? ? Bony
? ?
8
Jawless Cartil. Bony
Tetrapods
Fish
time
Ribosomal RNA tree
9
Jawless Cartil. Bony
Tetrapods
Fish
Bone loss
Land
time
Jaws
Bone
10
BONES JAWS
11
THREE STEPS
GAIN OF BONE BY EARLY VERTEBRATES GAIN OF JAWS
BY FISH REDUCED BONE IN SHARKS RELATIVES
12
GAIN OF BONE BY EARLY VERTEBRATES CONODONTS
13
GAIN OF BONE BY EARLY VERTEBRATES CONODONT
ANIMALS
14
JAWLESS FISH
HAGFISH dead, dying prey LAMPREYS small
prey larger hosts
15
JAWLESS FISH LAMPREY
16
FINS
LIVING JAWLESS, e.g. LAMPREY ONLY ALONG BODY
17
EXTINCT JAWLESS FISH
Paired Fin
18
JAWS
Conodont fossils look rather like jaws Perhaps
origin of jaws if muscles added
19
FINS
LIVING JAWED FISH HAVE PAIRED FINS
GIRDLE
SUPPORTS
FIN RAYS
20
CARTILAGINOUS FISH
Buoyancy problems since have no
swimbladder Partially solved by squalene in liver
21
CARTILAGINOUS FISH
SHARKS open-water RAYS shallow
sea bed RATFISH deep sea bed
22
SHARKS CARNIVORES
23
SHARKS FILTER FEEDERS
24
RAYS MOLLUSC-EATERS
25
RATFISH MOLLUSC-EATERS
26
BONY FISH
RAY-FINNED gt27, 000 species LOBE-FINNED 8
species
27
RAY-FINNED BONY FISHRULE
28
LOBE-FINNED BONY FISH
COELACANTHS LUNGFISH
29
LOBE-FINS
30
GILLS LUNGS
Basking Shark
31
GILLS LUNGS
GILLS
LUNG
32
CLASS SPLIT INTO3 GRADES
Gills? Lung? Jawless ?
X Cartilaginous ? X Bony
most some
33
LUNGFISHHAVE GILLS LUNGS
No change from early Bony Fish
34
RAY-FINNED FISHHAVE LOST LUNGS
Gas-filled swimbladder
35
COELACANTHSHAVE LOST LUNGS
Fat-filled swimbladder
36
Early bony fish in freshwater
Ray-fins Sea Swimbladder
Lungfish FW Aestivation
Coelacanths Sea Swimbladder
37
INVADING LAND
38
INVADING LANDTO GET WATER
39
INVADING LANDTO GET FOOD
40
INVADING LANDTO AVOIDPREDATORS
41

EARLY AMPHIBIANS LOOK AQUATIC
FINNED TAIL
DIGITS
42

EARLY AMPHIBIANS SWITCHED TO REAR WHEEL DRIVE