Monterey Bay Aquarium Research Institute
Marine Botany

Dinoflagellate Habitat, Ecology, and Behavior


Dinoflagellates live in the top 200 feet of the ocean. They like the sunlight, and they live with a lot of other plankton: other phytoplankton like the diatoms, and a lot of zooplankton.

This is a copepod. They tend to be about a quarter to a half of a millimeter in length, and they love to eat phytoplankton. Dinoflagellates are eaten more by copepods than by any other organism. But dinoflagellates are also eaten by corals, anemone, tunicates, mussels, clams, and even whales!

This is another phytoplankton. Do you know what it is? It has no tail for swimming, so it tends to sink. They are much more abundant than dinoflagellates in the Monterey Bay. The same things that eat dinoflagellates also may eat these guys.


Dinoflagellates usually photosynthesize their food, but some can eat very small organisms and even other dinoflagellates! Some are symbiotic. That means they live in harmony with other organisms, like corals and anemones. In fact, the green anemone found commonly around the Monterey Bay would be white without their dinoflagellate symbionts! 

And corals die without dinoflagellates to photosynthesize for them. In return, dinoflagellates get shelter and protection from the organisms they feed.

Last updated: Feb. 05, 2009