Four-horned green alga
Tetraedron minimum
The four-horned green alga is a widespread, single-celled freshwater green alga from the family Chlorococcaceae. Its cells exhibit a distinctive tetrahedral or flat-square shape with concave margins, with the corners often ending in short, tooth-like points. It lives primarily planktonically in stagnant or slow-flowing waters and prefers nutrient-rich conditions. Reproduction occurs asexually through the formation of two to eight autospores within the mother cell.
Details
Oxygen production
Produces oxygen as a byproduct of photosynthesis in the epilimnion.
Habitat function
Serves as food for filter-feeding zooplankton.
Nutrient uptake
Absorbs dissolved inorganic nutrients such as nitrate and phosphate from the water.
Food source for
Daphnia, rotifers, and other microherbivores.
Human use
Occasionally used in research to study algal morphology and taxonomy.
Ecology
Ecological role
Important primary producer; forms the basis of the aquatic food web.
Natural predators
Zooplankton (e.g., rotifers, daphnia).
Competitor species
Other planktonic green algae and cyanobacteria.
Ecosystem service
Oxygen production through photosynthesis and carbon fixation.
Threats
Excessive pesticide contamination in water bodies.
Scientific profile
Profile
Distinguishing features
Characteristic tetrahedral shape with concave margins; a single large parietal chloroplast filling most of the cell and containing a distinct pyrenoid. The cell wall is firm, smooth or finely punctate, and primarily composed of cellulose.
Reproduction
Asexual reproduction via the formation of 4 or 8 (rarely 16) autospores within the mother cell, which are released by the rupture of the cell wall.
Protection & threats
Status not on standard scale
Main threats
General degradation of water quality due to toxic pollutants; however, the species itself often benefits from anthropogenic eutrophication.
Conservation measures
No specific species conservation measures required; general protection of aquatic habitats and nutrient budget management.