Mulberry Alga
Sphaeroplea annulina
The Mulberry Alga is a filamentous green alga primarily found in shallow, ephemeral freshwater habitats such as puddles, ditches, and flooded meadows. It forms unbranched filaments composed of long, cylindrical cells containing numerous nuclei and annular (ring-shaped) chloroplasts. The alga is particularly noted for its brick-red, thick-walled resting spores (oospores), which cluster within the cells and give the species its common name. These spores allow the organism to survive extreme periods of desiccation and can remain viable in the soil for several years.
Details
Oxygen production
High oxygen production during growth phases in sunlight.
Habitat function
Provides structure and food in ephemeral waters for microorganisms.
Nutrient uptake
Rapid uptake of nitrogen and phosphorus during the growth period.
Food source for
Food source for aquatic invertebrates and tadpoles.
Human use
Scientific research subject for cell biology studies and the investigation of survival strategies.
Ecology
Ecological role
Primary producer in short-lived aquatic ecosystems; pioneer species following rainfall events.
Natural predators
Zooplankton, particularly Daphnia and various insect larvae.
Competitor species
Other filamentous green algae such as Spirogyra species or small phytoplanktonic algae.
Ecosystem service
Oxygen enrichment in small water bodies and sequestration of dissolved nutrients.
Threats
Destruction of temporary water bodies through soil sealing, drainage, and intensive agriculture.
Scientific profile
Profile
Reproduction
Oogamy; vegetative cells differentiate into oogonia or antheridia; formation of thick-walled, ornamented oospores as resting stages to survive dry periods.
Protection & threats
Status not on standard scale
Main threats
Loss of temporary small water bodies due to drainage, floodplain regulation, intensive agricultural use, and general eutrophication.