FIFTH PLACE: This young sea star—or starfish, of the class Asteroidea—may have been smiling for the dark-field microscope when this image was taken, but judging from its oral surface, shown here at 40 times life-size, even Bruno Vellutini of the Centro de Biologia Marinha at the University of São Paulo in Brazil, who took the image, may not know... BRUNO VELLUTINI