List of cnidarians of Ireland

There are 302 species of cnidarians (phylum Cnidaria) recorded in Ireland.[1]

The cnidarians' distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick. They have two basic body forms: swimming medusae and sessile polyps, both of which are radially symmetrical with mouths surrounded by tentacles that bear cnidocytes. Both forms have a single orifice and body cavity that are used for digestion and respiration. Many cnidarian species produce colonies that are single organisms composed of medusa-like or polyp-like zooids, or both (hence they are trimorphic).[2][3][4]

Cnidarians found in Ireland and Irish waters include sea pens, sea anemones, hydroids, sea jellies ("jellyfish") and corals.