jellyfish with flashy neon light background

>This article is about jellyfish, the sea creatures. For the pop band, see Jellyfish (band). Stauromedusae Coronatae Semaeostomeae - Disc jellyfish Rhizostomae Jellyfish (also called jellies or sea jellies as they are not true fish, nor are they made of jelly) are animals that belong to Phylum Cnidaria, included in the class Scyphozoa (from Greek skyphos "cup" and zoon "animal"). The name "jellyfish" is also often used for the related classes of medusae (Hydrozoa) and box jellyfish (Cubozoa). Almost all jellyfish live in the seas and though they lack true organ structures they feature specialized tissues. The adult forms of these creatures are composed of 94-98% water. All species are found in each of the world's oceans, with a few species living in fresh water. Most jellyfish are passive drifters that feed on small fish and zooplankton that become caught in their tentacles. Jellyfish have an incomplete digestive system, meaning that the same orifice is used for both food intake and waste expulsion. They are Coelenterates which means "hollow gut", and are made up of a layer of epidermis, gastrodermis, and a thick jelly-like layer called mesoglea that separates the epidermis from the gastrodermis. See more at Wikipedia.org...