Noctiluca scintillans is a unique athecate species with large, balloon-like and subspherical cells. These cells have a deep ventral groove housing a flagellum, a tooth, and a striated tentacle that extends backward. Unlike many dinoflagellates, it possesses only one flagellum, serving a role similar to the transverse flagellum in others. Reproduction occurs both asexually through binary fission and sexually via isogamete formation. Notably, the vegetative cell is diploid, while the gametes are haploid and display gymnodinioid characteristics with dinokaryotic nuclei.