Fragilaria intermedia is a diatom species characterized by elongated, rectangular cells that form ribbon-like colonies. Its silica cell walls, called frustules, display fine, evenly spaced striae running parallel to the cell’s long axis. In valve view, cells appear narrow with parallel sides and rounded ends, while in girdle view, they look like thin bands. These morphological features are used for identification under a microscope. Fragilaria intermedia plays a crucial role as a primary producer in aquatic ecosystems and serves as an indicator of water quality.