homeChapter 12 Fishes and Amphibians
I. Vertebrates
A. Animal with a backbone
1. Endoskeleton
2. Made of living tissue
3. Grows as animal grows
B. Belong to phylum Chordata
1. Called chordates
2. Three important characteristics
a. Nerve cord
b. Notochord
c. Throat with gill slits
3. Eight groups of vertebrates
a. Six are coldblooded
b. Two are warmblooded
II. Fishes
A. Water-dwelling vertebrates
B. Have similar characteristics
1. Scales
2. Fins
3. Throats with gill slits
C. Have closed circulatory system
D. Well-developed nervous system
E. Keen senses of smell and taste
F. Reproduction
1. Internal fertilization
2. External fertilization
G. Three groups of fish
1. Jawless
a. Most primitive
b. Lack jaws, scales, paired fins
c. Skeleton made of cartilage
Example: lampreys, hagfishes
2. Cartilaginous
a. Skeleton made of cartilage
b. Body covered with scales
c. Have teeth
Example: sharks, skates
3. Bony fish
a. Skeleton made of hard bone
b. Travel in groups called schools
c. Have paired fins
d. Have swim bladders
Example: flounder, trout
III. Amphibians
A. Means double life
B. Are fishlike
C. Breathe through gills when immature
D. Breathe through lungs on land
E. Have moist skin
1. Contains glands
2. Lack scales and claws
F. Eggs lack hard outer shell
G. Circulatory system forms double loop
H. Have well-developed nervous system
I. External fertilization
J. Frogs
1. Smooth, moist skin
2. Undergo metamorphosis
K. Toads
1. Wartlike bumps on skin
2. Poisonous liquid in bumps behind eyes
L. Salamanders and newts
1. Two pairs of legs
2. Not able to jump
3. Live in moist areas
4. Lay eggs in water
