Small red cryptomonad
Rhodomonas minuta
The Small Red Cryptomonad is a unicellular flagellate belonging to the class Cryptophyceae. It is characterized by a distinctive reddish to brownish coloration provided by the accessory pigment phycoerythrin. The cells are typically oval or kidney-shaped and possess two flagella of unequal length inserted into a gullet-like depression (gula). As an important primary producer, it serves as a high-quality food source for zooplankton.
Details
Oxygen production
Significant oxygen release during the light phase as a byproduct of photosynthesis.
Habitat function
Primary producer in the pelagic zone of standing and slow-flowing waters.
Nutrient uptake
Efficient uptake of inorganic nitrogen and phosphorus from the water column.
Food source for
Filter-feeding zooplankton and larval fish.
Human use
Used in research and aquaculture as a standard food organism for maintaining zooplankton cultures.
Ecology
Ecological role
Important base of the pelagic food chain; an essential resource for herbivores due to its high content of polyunsaturated fatty acids.
Natural predators
Zooplankton such as rotifers (Rotatoria) and cladocerans (e.g., Daphnia).
Competitor species
Other phytoplankton such as diatoms (Bacillariophyceae) and green algae (Chlorophyceae) competing for light and nutrients.
Ecosystem service
Oxygen production through photosynthesis and carbon fixation in the limnic ecosystem.
Threats
Severe eutrophication (leading to dominance of cyanobacteria) and chemical pollution from herbicides.
Scientific profile
Profile
Distinguishing features
Possesses a deep gullet lined with ejectosomes. Two flagella of slightly unequal length emerge from the gullet margin. A single, large, reddish chloroplast with one pyrenoid is present.
Reproduction
Asexual reproduction by simple longitudinal fission of the cell in the motile state.
Protection & threats
Status not on standard scale
Main threats
Strong eutrophication can lead to displacement by cyanobacteria; herbicide input from agriculture.
Conservation measures
Maintenance of near-natural nutrient dynamics; reduction of diffuse nutrient inputs into lakes.