The Nikon MicroscopyU confocal microscopy image gallery was created with a PCM-2000 confocal scanning system interfaced to a Nikon Eclipse E600 upright microscope. Images were recorded in successive z-axis serial sections with C-Imaging Systems software with excitation illumination provided by an argon-ion and/or a helium-neon laser.

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Dinoflagellates (Peridinium) are single-celled organisms that propel though watery environments by waving two thread-like structures referred to as flagella. These mostly marine creatures are participants in plankton communities that drift along sea currents and serve as an important source of food for many aquatic animals. The two flagella are situated in such a way that their combined action causes the organism to slowly turn on its axis as it moves through the water. Uni-celled organisms that display this characteristic movement fall within a category termed dinoflagellate, which means "whirling flagella" in Greek.

Many peridinium are photosynthetic and able to convert sunlight into food sources such as carbohydrates. Nonphotosynthetic species may be phagotrophic and digest bacteria or other single celled creatures after first engulfing them. Osmotrophs are the simplest forms and absorb nutrients released from organic matter directly through their membranes. Photosynthetic varieties are frequently studied by biologists that investigate the structure and function of cell nuclei and circadian rhythms.

More advanced species of peridinium display plant and animal like characteristics and contain an eyespot or light sensitive area, which is composed of lipid droplets set between layers of membrane. These pigment proteins, termed carotenoids, respond to light and stimulate the minute organism to move toward the source. The membrane surface also contains vesicles called trichoysts, which discharge crystalline rods as a mechanism for self-defense.

When occurring in large numbers, some forms of peridinium can cause water discoloration in estuaries and along coasts known as "red tide". Although imparting a beautiful luminescence to water, some forms may release toxins deadly to animal life.