Dinoflagellates form a unique group of unicellular organisms. They are a big part of the plankton community. Some species are plant-like organisms and grow from sunlight (autotrophic). Other dinoflagellate species have more animal-like characteristics and feed on other micro-organisms (heterotrophic).
Dinoflagellates form a unique group of unicellular organisms. They are a big part of the plankton community. Some species are plant-like organisms and grow from sunlight (autotrophic). Other dinoflagellate species have more animal-like characteristics and feed on other micro-organisms (heterotrophic).
Double engine
Dinoflagellates live in large numbers as plankton in both freshwater- and marine environments. While most planktonic species cannot swim actively, dinoflagellates are able to adjust their direction a little bit with their two flagella. One flagellum is attached at the back and pushes the cell forward like a ship’s propeller. The other flagellum is wrapped around the cell. It enables the cell to make a spinning motion.
Click with corals
Individual dinoflagellates cannot be seen with the naked eye. Most species live freely in the water. However, some species permanently live together with corals. Many corals depend on dinoflagellates or other unicellular organisms that live in their cells. The symbiotic dinoflagellates use sunlight to produce building materials for the corals. The corals, in turn, provide space for growth and secrete substances that the dinoflagellates can use. Rising sea water temperatures lead to a disturbance of this symbiosis; if the water temperature is too warm, the corals repel their internal guests. This phenomenon is called coral bleaching and is harmful to the colour and survival of the coral.
Flashy feature
If you have ever made nocturnal walks on the beach, you might have spotted a blue-green glow on the waves. Or you noticed that your footsteps in shallow water had an afterglow. If you recognize this, you have met the dinoflagellate Noctiluca scintillans, commonly known as sea sparkle. Multiple dinoflagellate species have this flashy feature, a phenomenon called bioluminescence. Producing a flash protects the dinoflagellate from enemies. Not only are they confused by the dazzling flash of light, the enemies themselves can also be spotted more easily now by even bigger predators.
Do you want to know more about bioluminescence? Visit the exhibit “Illuminators” in Micropia.