Dinoflagellates
Dinoflagellata
Dinoflagellates are a group of unicellular organisms that primarily inhabit marine and freshwater environments as part of the phytoplankton. They are characterized by a cell wall composed of cellulose plates, giving them an armored appearance. A defining feature is the presence of two distinct flagella located in grooves of the cell wall, enabling a characteristic whirling swimming motion. Many species are mixotrophic, combining photosynthesis with the ingestion of organic matter.
Details
Oxygen production
Significant contribution to global oxygen production via photosynthesis.
Habitat function
Primary production and provision of biomass; reef formation through symbiosis.
Nutrient uptake
Uptake of phosphates and nitrates from the water.
Food source for
Zooplankton, larvae, bivalves.
Human use
Research, partly problematic due to toxin production during algal blooms.
Ecology
Ecological role
Important primary producers and symbiotic partners in corals (zooxanthellae).
Natural predators
Zooplankton, small fish, filter feeders.
Competitor species
Diatoms, cyanobacteria.
Ecosystem service
Oxygen production and base of the marine food web.
Threats
Ocean acidification, climate change, and extreme eutrophication.
Scientific profile
Profile
Distinguishing features
Two distinct flagella (heterokont): a longitudinal flagellum in the sulcus and a transverse flagellum in the cingulum, providing a rotating swimming motion. Presence of cellulose armor plates in thecate species. Many species are mixotrophic or bioluminescent.
Reproduction
Primarily asexual through binary fission (schizogony). Sexual reproduction usually occurs under stress conditions, leading to the formation of diploid resting cysts (hypnozygotes).
Protection & threats
Status not on standard scale
Main threats
Eutrophication of water bodies, ocean acidification, and rising water temperatures due to climate change.
Conservation measures
Reduction of diffuse nutrient inputs from agriculture, surveillance through HAB monitoring programs, and protection of marine habitats.