| A | B |
|---|
| Cnidaria | phylum of animals that includes jellyfish, corals, hydras, and sea anemones |
| cnidarians | updated name for the simple, sac-shaped, water-dwelling animals that were once called "coelenterates" (such as jellyfish, etc.) |
| radial | type of body symmetry that all cnidarians have |
| mouth | the only opening that cnidarians have leading into or out of their central cavity |
| tentacles | arm-like appendages that surround the mouth of a cnidarian |
| nematocysts | stinging cells that are buried in the surface of the tentacles of most cnidarians; for paralyzing their prey |
| marine | all corals live in this kind of water environment |
| fresh water | all hydras live in this kind of water environment |
| polyp | most cnidarians have this body shape (somewhat rectangular with tentacles pointing upwards) |
| medusa | the body shape that some cnidarians have which is cup-like with tentacles hanging down |
| jellyfish | this common cnidarian has the medusa body shape |
| sea anemone | the red clownfish is immune to the stinging nematocysts of this cnidarian |
| Portuguese Man-of-War | very dangerous jellyfish-like colony of hydrazoans with one large gas-filled polyp that acts as a float |
| reef | years of coral skeletons build up to become large underwater mound called a __. |
| sessile | the sea anemone is a __ animal, meaning it stays put in one spot all of its adult life |
| hydra | this polyp-shaped cnidarian is not sessile and it only lives in fresh water |
