The cells of this species typically fall within a size range of 80-400 µm in length, and they are notably flattened in a dorsoventral direction. One of the distinguishing features is the long and narrow apical horn, which terminates in a blunt tip. Additionally, the antapical horns are straight in shape and have pointed tips, which are typically closed. Towards their distal ends, the antapical horns tend to slightly diverge from each other. In certain instances, there may be a third antapical horn present, further enhancing the species’ unique morphology.Ceratium hirundinella is known to be capable of forming short chains of cells. One of its remarkable ecological attributes is its wide salinity tolerance, allowing it to adapt and thrive across varying salinity levels in aquatic environments.