cnidarians are defined by the presence of
Cnidaria. Cnidaria is a phylum of animals, which contains amazingly beautiful coral reefs, electrifying jellyfish, and many other interesting oceanic creatures. There are about 10,000 species of cnidarians and all of them are unique among all other organisms for the presence of the Cnidocytes. Cnidaria and porifera are two different phyla. â¢ Cnidarians have Cnidocytes but not the poriferans. â¢ Cnidarians have well-organized organ systems but not the poriferans; on the other hand, poriferans have an efficient tunnel system made up of pores but not the cnidarians.