Asterionella formosa is a diatom species characterized by its chain-like structure of cylindrical cells aligned linearly. Each cell is elongated and rectangular, with parallel sides and rounded ends, forming straight or gently curved filaments.The silica cell walls of Asterionella formosa are intricate and fragile, marked by longitudinal striations that are more prominent towards the cell ends. Each cell features a narrow axial area running along its length, slightly wider than the raphe—a slit-like structure that extends along the cell’s surface. Terminal nodules are present at the ends of the raphe near the cell poles. Commonly found in freshwater environments like lakes and ponds, Asterionella formosa plays a vital role as a primary producer in the aquatic ecosystem.