Porpita

Porpita porpita, commonly known as the blue button, is a marine organism consisting of a colony of hydroids found in tropical and sub-tropical waters of the Pacific, Atlantic, and Indian oceans. Although it is superficially similar to a jellyfish, each apparent individual is actually a colony of hydrozoan polyps. The blue button is a Chondrophore, which is a group of cnidarians that also includes Velella and Porpema. The chondrophores are similar to the better-known siphonophores, which...