| A | B |
|---|
| arthropods | jointed leg animals |
| exoskeleton | composed of chitin |
| molt | shedding of exoskeleton |
| antennae | used to sense surroundings |
| barnacles | filter feeders that live attached to surfaces; body enclosed by heavy plates |
| decapods | 10 legs: shrimps, lobsters, and crabs |
| cephalothorax | head and thorax region of lobster |
| pentamerous | symmetry based on 5 parts |
| echinoderms | spiny skinned animals |
| water vascular system | network of water-filled canals |
| tube feet | muscular extensions of water vascular system |
| madreporite | porous plate on aboral surface |
| endoskeleton | internal skeleton |
| regeneration | ability to grow lost or damaged body parts |
| notochord | flexible rod for support lying betwwen nerve cord and gut |
| nerve cord | runs along dorsal length of animal |
| postanal tail | tail that extends beyond anus |
| pharyngeal slits | small openings along gut; develop into gills |
| tunicates | sea squirts, covered by a tunic |
| lancelet | looks like a fish, but has no backbone |
