Rhopalodia gibba is a diatom species known for its distinctive crescent or boat-shaped cells. Its silica cell walls, or frustules, have a unique canal raphe system for movement and exhibit evenly spaced striae. In valve view, the cells appear elongated with a noticeable curvature, while in girdle view, the curvature is more pronounced. Rhopalodia gibba serves as a primary producer in aquatic ecosystems and is useful for environmental studies and water quality assessments due to its unique morphology and ecological role.