Red Tide


Karenia brevis is a mixotrophic organism. This means that Karenia brevis is able to assimilate inorganic and organic carbon using the combination of heterotrophic and autotrophic modes, and because of these modes together, it can acquire its nutrients.

National Oceanic and Atmospheric Administration

Being a mixotrophic dinoflagellate, Karenia brevis can ingest picoplanktonic organisms and/or photosynthesize as their means of acquiring nutrients. In K. brevis' heterotrophic mode it grazes on picoplankton in the Gulf of Mexico which shortens the transfer of dissolved organic material by the microbial loop.  Picoplankton is abundant and provides necessary nutrients to allow K. brevis to initially bloom, and permits the blooms. Picoplankton maintains the 'seed' population of K. brevis offshore. Dinflagellates, along with K. brevis can graze; however, grazing by K. brevis on co-occurring picoplankton in the Gulf of Mexico has been short studied.

NOAA - National Centers for Costal Ocean Science

Not only can this organism get its nutrients by heterotrophism it can get its nutrients by autotrophism. Being an auxotroph it can acquire its nutrients by photosynthesis. The equation is shown below. From photosynthesis K. brevis can get its nutrients from the sugar produced called glucose.

6CO2 + 6H2O + ATP --> C6H12O6 + 6O2

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