Dinoflagellates are a group of microscopic one-celled microorganisms.
Most are free swimming and are plant-like, that is, they have the ability to obtain energy by photosynthesis. A natural part of the environment, dinoflagellates are nontoxic organisms. Pfiesteria piscicida, however, is an exception to that rule. In 1988, Dr. JoAnn Burkholder, an aquatic ecologist at North Carolina State University, discovered the organism, and declared it a new species in a new genus and a new family in the order Dinamoebales. Burkholder and her associates named the new organism Pfiesteria after the late Dr. Lois Pfiester, a researcher of dinoflagellates.