Simple Animals

1. a type of invertebrate animal that is a member of the phylum Cnidaria, which also includes jellyfish and sea anemones
6. microscopic, hair-like structures that help cells move
8. a genus of small, tube-shaped calcareous sponges belonging to the family Sycettidae
9. small openings or pores in the body of an animal or in its organs
10. the large, central cavity of a sponge that's also known as the paragaster
13. having both male and female reproductive organs in the same individual
14. an excretory structure in the living sponge, a large opening to the outside through which the current of water exits after passing through the spongocoel
17. small, needle-like structures that can be found in various organisms, including sponges and nematodes
18. a larval stage of some cnidarians and ctenophores that is free-swimming, flattened, and ciliated
19. animals that live on, in, or near the bottom of a body of water
21. a form of asexual reproduction where a new organism develops as a small outgrowth or "bud" from the body of a parent organism, eventually detaching to become a separate individual

2. a collective term for organisms that live in water and are carried by currents and tides because they are too small or weak to swim against them.
3. an animal or plant that has both male and female reproductive organs, structures, or tissue
4. having distinct individuals that are either male or female, and produce either male or female gametes
5. the immature form of an animal that hatches from an egg or is born, and that must undergo metamorphosis to become an adult
7. a sponge or sponge larva with a simple canal system
8. an organism that is permanently attached to a surface and cannot move freely
11. a type of sponge with a complex structure that includes a thick body wall and a highly branched canal system
12. an animal that eats by filtering food particles or small organisms from water
15. the free-swimming, bell-shaped body form of a cnidarian
16. a flexible, organic material that forms the fibrous skeleton of most sponges
20. For example, contractile proteins are found in muscle fibrils.