Blue rays

Is it fireworks, a flower, or a 1970’s fiber-optics lamp? None of the above!—it’s a colonial ocean animal related to jellyfish, called Porpita porpita. The colony has radiating blue “tentacles”—really the individual units of the colony— that sting and catch tiny animals, and a gas-filled float to help it stay at the ocean surface. This and other “jellies” are featured on a poster available at the WHOI store. (Photo by Larry Madin, Woods Hole Oceanographic Institution)