Chrysophytes are a group of microscopic unicellular or colonial eukaryotic algae. Once classified with the diatoms and brown algae, they are also within the kingdom Chromista, phylum heterokontophyta. Chrysophytes have two flagella that are unequal in length. On the short flagellum, there is a photoreceptor, and they also have a stigma (eyespot) in one of the chromoplasts. Many Chrysophytes are single-cell organisms that swim independently, while others form colonies that tumble through the water and may superficially resemble the motile colonies of green algae. Some are found attached to various substrata, and no motile stage has been observed.