Oval Diatom
Surirella ovalis
The Oval Diatom is a unicellular, photosynthetically active organism belonging to the class Bacillariophyceae. It is characterized by a bilaterally symmetrical, oval-shaped silica shell (frustule) featuring a wing-like canal along the margin containing the raphe. This species lives predominantly benthically on sediment surfaces in both lentic and lotic waters, though it can also be found in plankton. It is an important primary producer and serves as a fundamental food source for numerous aquatic microorganisms.
Details
Oxygen production
High relative to biomass due to efficient photosynthesis.
Habitat function
Colonizes surfaces and stabilizes sediment through the production of biofilms (extracellular polymeric substances).
Nutrient uptake
Efficient uptake of dissolved silicates for frustule construction as well as nitrate and phosphate.
Food source for
Micro-organisms, fish larvae, and benthic grazers.
Human use
Indicator organism in limnology for monitoring water quality.
Ecology
Ecological role
Important primary producer in aquatic systems; fixes carbon and forms part of the base of the food web.
Natural predators
Zooplankton (e.g., Daphnia), benthic invertebrates, protozoa.
Competitor species
Other diatom species, green algae, and cyanobacteria competing for light and nutrients.
Ecosystem service
Oxygen production and sequestration of atmospheric CO2.
Threats
Water pollution, herbicide runoff, extreme acidification of water bodies.
Scientific profile
Protection & threats
Main threats
Loss of shallow water habitats due to bank stabilization, extreme toxic pollution, and strong acidification (prefers alkaline environments).