Solar-cell nudibranch
suggested by John Beland

Pteraeolidia ianthina, commonly known as the ``blue dragon'' by divers in eastern Australia, is an aeolid from a group of remarkable nudibranchs which are way ahead of man in harnessing solar energy. It has evolved a method of capturing and farming microscopic plants (zooxanthellae) in its own body. The plants flourish in this protected environment and as they convert the sun's energy into sugars, they pass a significant proportion on to the nudibranch for its own use. The white animal is a juvenile which as not yet developed its crop of zooxanthellae.