Blue Button Drifter

Porpita porpita, also called the blue button jelly, floats at or near the surface of the water and drifts with the wind. This flower-like floater, related to jellyfish, is actually a colony, not a single animal. Its blue central disc is filled with a gas that allows the colony to float. The tentacles radiating from the disc are individual polyps specialized to do all the feeding.(Photo by Kelly Rakow Sutherland, Woods Hole Oceanographic Institution)