A worldwide community photographing and learning about wildlife
Porpita porpita
Porpita porpita, commonly known as the blue button, is a marine organism consisting of a colony of hydroids found in tropical waters from California to the tropical Pacific, the Atlantic and Indian ocean It is often mistaken for a jellyfish, but although jellyfish and the blue buttons are part of the same phylum (Cnidaria), the blue button is part of the class Hydrozoa. Wikipedia
Found in shallow sandy water 1-2 feet off Mokauea Island
As they were floating around the students counted about 10! When touched it retracted.