Echinoderms & Arthropods

4. Bulb-like sacs that control tube feet by pumping water.
5. The main body area where the arms attach.
7. Fixed in one place; does not move.
8. The side opposite the mouth.
9. Small calcium carbonate plates that make up an echinoderm's internal skeleton.
11. Body plan arranged in five parts around a central axis.
14. Living on or near the ocean floor.
15. A large group of invertebrates with jointed limbs, segmented bodies, and a hard exoskeleton.
17. Tiny, planktonic crustaceans found in oceans and freshwater; important part of the aquatic food chain.
19. The last segment of an arthropod’s body, often forming a tail-like structure.
20. The rear section of the body in arthropods, often containing digestive and reproductive organs.

1. A species that has a disproportionately large impact on its ecosystem.
2. Appendages near the mouth used for feeding and handling food.
3. Small, flexible structures used for movement, feeding, and attachment.
6. A hard, protective shell covering the back of some arthropods.
10. The ability to intentionally shed a body part
12. Canals that extend from the ring canal into each arm.
13. A skeleton located inside the body.
16. A sieve-like opening where water enters the water vascular system.
18. Marine invertebrates with spiny skin, radial symmetry, and a water vascular system.