Spirulina platensis is a filamentous cyanobacterium found in alkaline freshwater environments, especially in warm, tropical regions. It appears as long, spiral-shaped strands composed of multicellular trichomes. Each cell is small, typically ranging from 0.5 to 1 μm in diameter, with a cylindrical shape and rounded ends. The cell wall is thin and flexible, contributing to its filamentous structure. Spirulina platensis is known for its blue-green coloration, attributed to the presence of phycocyanin and chlorophyll pigments. Reproduction primarily occurs through the fragmentation of trichomes.