Chapter 25

5. a four-footed animal, especially a member of a group which includes all vertebrates higher than fishes.
6. system a row of sensory organs running along the sides of the body
8. an internal skeleton, such as the bony or cartilaginous skeleton of vertebrates.
9. the tailed aquatic larva of an amphibian
11. on each side of the fish witch is a protective flap
12. live part of their life on land and water

1. a cartilaginous skeletal rod supporting the body in all embryonic and some adult chordate animals.
2. each of the series of small bones forming the backbone
3. an animal of the large phylum Chordata, comprising the vertebrates together with the sea squirts and lancelets.
4. fish a fish of a class distinguished by having a skeleton of cartilage rather than bone, including the sharks, rays, and chimeras.
7. fish. a fish of a large class distinguished by a skeleton of bone, and comprising the majority of modern fishes.
10. bladder a sac that regulates buoyancy