Bladderwort: tiny carnivorous plant
© I. Siwanowicz/HHMI Janelia Farm Research CampusBig Mouth: The trap of this carnivorous bladderwort is only 1.5 millimeters long, but under a microscope it looks much more menacing.
Under a microscope, the tiny trap of a carnivorous plant becomes an impressive gaping maw. Rootless and adrift in its wetland habitat, the humped bladderwort (Utricularia gibba) preys on water fleas and other small invertebrates. Organisms that trip the plant's sensory hairs are sucked inside bladderlike traps to be digested.

Neurobiologist Igor Siwanowicz of the Janelia Farm Research Campus in Ashburn, Va., created this psychedelic image of a bladderwort's trap using fluorescent dye to tag the cellulose in plant cell walls. This trap was just 1.5 millimeters long, so he magnified the image 100 times to reveal minuscule details, including digestive glands that line the trap's inner wall (red crosses). The plant also sports some microscopic hitchhikers: single-celled green algae living inside the trap (red-and-blue disks, three species shown). Algae escape digestion by squatting in older, inactive traps.

In December, Siwanowicz's photo took first place in the 2013 Olympus BioScapes Competition, an international contest for life science images.