Jellies: jellyfish and other gelatinous or transparent life forms

Aquatic environments favor nearly transparent organisms since they are almost invisible to their predators and prey. Hence there is a large diversity of transparent life forms in the ocean. This includes the familiar true jellyfish or Scyphozoa of the phylum Cnidaria also know as Coelenterata. Other gelatenous cnidarians include the Hydrozoa and box jellyfish (Cubozoa). Another phylum of gelatinous forms are the comb jellies or Ctenophora. The pelagic tunicates (of phylum Chordata) include the spectacular Thaliacea. As well, there are jellylike transparent mollusks and larval stages of many organisms.