I wanted to choose a unique organism that lives under the depths of the ocean. These creatures are bioluminescence which means they glow. This is my interpretation of “Ceratium” which is like plankton in the ocean. Ceratium species are easily identifiable because of their unique shape. They are covered with an armor-like cell wall, made out of polysaccharidel. The most distinguishing characteristic are the arms (also known as horns), the shape and size of which vary from species to species. Ceratium monoceras has a single, apical horn. The arms help Ceratium float, but prevent them from moving very quickly. Ceratium contain peridium. Another important feature is that they contain small plasmids (minicircles). Ceratium have two flagella. This wind around the cell body. The flagella each have different movements and shapes. The transverse flagellum beats in a spiral motion, while the longitudinal flagellum pulses in waves. Most Ceratium species also contain chloroplasts. Certain species are bioluminescent. Under adverse conditions, Ceratium are able to encyst themselves as a form of protection. Ceratium are aquatic organisms, living in both marine and freshwater environments. They are most common in temperate areas, but can be found all over the world. Ceratium are found in the mesopelagic regions of the water. Unlike other dinoflagellate species such as Alexandrium, Ceratium are relatively harmless organisms. They are non-toxic, and are necessary for the food web. However, they can cause a red tide if conditions allow for excessive blooming. While this red tide is not toxic, it can deplete resources in its environment, causing strain on the ecosystem. In general, though, Ceratium are necessary components of their habitats. They serve not just as nutrients for larger organisms, but they keep smaller organisms in check through predation.