Many dinoflagellates are either photosynthetic, photoautotrophic, or heterotrophic. Gonyaulax catenella happens to be photoautotrophic, meaning this organism converts light into food energy through photosynthesis. A simple chemical equation to describe photosynthesis is as follows: carbon dioxide + water + light ---> produces glucose and oxygen. Another organism that uses photosynthesis to acquire nutrients is the Bracken Fern. Check it out!

General Photosynthesis Equation, Zoofari, Wikimedia Commons, 2010.
      Zoofari, Wikimedia Commons, 2010.

     Unlike other dinoflagellates, Gonyaulax catenella does not possess an eyespot. Instead, photosynthetic regions are located near the base of its flagella. Chloroplasts (a photosynthesizing organelle) contained within the lower body of the protist do the work of converting light energy into chemical energy. Within the chloroplasts are pigments for trapping light. These pigments are chlorophyll a, chlorophyll c, small amounts of diatoxanthin, diadinoxanthin, and peridinin— a xanthophyll (carotenoid) that is unique to dinoflagellates. To access their light source, G. Catenella can swim with a propulsion movement due to their flagella.  Cells form dense clusters near the ocean's surface, where they are able to easily photosynthesize. During the night, they take advantage of the higher nutrient concentration at greater depths due to differential light absorption of the water. The cells migrate through gradients  of different spectrums, obtaining different nutrient concentrations. Dinoflagellates can also photosynthesize with the help of circadian rhythms. These circadian systems respond to both short and long wavelengths of light. The combined action of red and blue light also active the chlorophyll.

Gonyaulax. © Smithsonian Environmental Research Center
© Smithsonian Environmental Research Center

Knowing how well G. catenella can acquire nutrients, take a look at their life complex cycle by going to the Reproduction page.

Curious to know how the Daffidil or E. coli reproduction cycles differ from that of a protist? Click the links to find out!