The World of Cnidaria
Cnidaria is a phylum that contains over 10,000 exclusively aquatic species. The body of a cnidaria contains mesoglea, which is a non-living jelly-like substance that is produced and placed between the inner layer and the outer layer of cells on the organism. Cnidaria have a single opening that is used for eating, and eliminating waste products. Cnidaria are all remarkably similar, particularly with respiration. See the sub-pages for species of Cnidaria and to learn more about cnidarian respiration!