Mixotrophy among dinoflagellates

Mixotrophy, used herein for the combination of phototrophy and phagotrophy, is widespread among dinoflagellates. It occurs among most, perhaps all, of the extant orders, including the Prorocentrales, Dinophysiales, Gymnodinia les, Noctilucales, Gonyaulacales, Peridiniales, Blastodiniales, Phytodinial es, and Dinamoebales. Many cases of mixotrophy among dinoflagellates are pr obably undocumented. Primarily photosynthetic dinoflagellates with their "o wn" plastids can often supplement their nutrition by preying on other cells . Some primarily phagotrophic species are photosynthetic due to the presenc e of kleptochloroplasts or algal endosymbionts. Some parasitic dinoflagella tes have plastids and are probably mixotrophic. For most mixotrophic dinofl agellates, the relative importance of photosynthesis, uptake of dissolved i norganic nutrients, and feeding are unknown. However, it is apparent that m ixotrophy has different functions in different physiological types of dinof lagellates. Data on the simultaneous regulation of photosynthesis, assimila tion of dissolved inorganic and organic nutrients, and phagotophy by enviro nmental parameters (irradiance, availability of dissolved nutrients, availa bility of prey) and by life history events are needed in order to understan d the diverse roles of mixotrophy in dinoflagellates.