Giant Clam among Coral Rubble

Old diving stories tell of giant clams snapping shut on a swimmer's foot, but there is no confirmed case of one drowning anybody. The shell closes slowly. The biggest adults can't even shut theirs all the way. This one sits open in a bed of coral rubble, its wavy mantle speckled blue and green around the round opening of its siphon. Those speckles give the giant clam jigsaw puzzle a lot of fine pattern.