Cnidaria: the phylum in which marine animals that are invertebrates with tentacles surrounding the mouth
polyp: sessile flower like cnidarian
medusa: motile bell shaped cnidarian
gastrovascular cavity: digestive cavity in cnidarians with only one opening
nematocyst: stinging structure on the tentacles of cnidarians that is used to paralyze or kill prey
hermaphrodite: individual that has both male and female reproductive organs
jellyfish:an invertebrate marine animal that, in its reproductive stage, has a nearly transparent gelatinous body shaped like an umbrella with trailing tentacles bearing stinging cells.
sea anemone:a solitary and often colorful sea animal with a squat cylindrical body that bears a ring of tentacles and is attached to rock or other nonliving material
coral:a marine organism that lives in colonies and has an external skeleton.