National Geographic : 1963 Aug
3 TIMES LIFE-SIZE Fluorescent tangle of pink and blue, stony algae spill across a lump of star coral. Blue-dotted ridges of rose coral show at upper left. Color differentiation under ultraviolet light provides a research tool in many fields. Fiery colors erupt from stony algae bathed by ultraviolet light. Feathery hydroid festoons a sprig of sargassum weed. Each bead on the branching filaments is a minute polyp. A single digestive tube joins all the colony's mouths. Natural light reveals a miniature world of sea life swarm ing about the weed's stalks and gas-filled floats. Bunodeop 270 sis anemones wave translucent tentacles on floats at left.