Question: what is the difference between a sea anemone and a sea urchin?
Answer: SEA ANEMONES Members of the coelenterate phylum, they are different from sea urchins which have a hard shell and long spines. Armed with stinging cells, the tentacles allow the anemone to paralyze small swimming animals which are then pushed into its mouth. ... Sea anemones take in oxygen and expel and carbon dioxide.