A beach stranded Portuguese Man-of-War (Physalia physalis). The Portuguese man-of-war is not a jellyfish, but a siphonophore, an animal made up of a colony of organisms working together. The purple structure in the picture is the uppermost polyp, a gas-filled bladder, or pneumatophore.

A beach stranded Portuguese Man-of-War (Physalia physalis). The Portuguese man-of-war is not a jellyfish, but a siphonophore, an animal made up of a colony of organisms working together. The purple structure in the picture is the uppermost polyp, a gas-filled bladder, or pneumatophore.