Bladderwort trap. Light microscopy footage of zooplankton (here, aquatic protozoa) swimming within a trap on a bladderwort plant (Utricularia). These carnivorous aquatic plants obtain energy by photosynthesis at the surface, catching aquatic zooplankton in its traps below the surface. The trapped animals are digested to provide phosphorus and nitrogen to the plant. This specimen is from the Kaw Marsh, French Guiana.