A multi-colored scallop sits open-mouthed on a reef off the Yap Islands in Micronesia. Unlike most mollusks, which tend to anchor themselves in colonies and stay put, scallops have the gift of locomotion. They move in short spurts by closing their mantle quickly, ejecting water and jet-propelling themselves backwards.

Scallops also have the distinction of eyesight. Their eyes, sometimes numbering more than a hundred, are quite sophisticated, each with a lens, retina, and optic nerve. These tiny peepers line the upper part of the mantle (seen as orange dots on this specimen) and work together to detect shadows and movements.

(Photo shot on assignment for, but not published in, "Manta!," December 1995, National Geographic magazine)