CalothrixCalothrix is a genus of cyanobacteria. They are generally found in freshwater.Removed membersSome members of the genus such as Calothrix rhizosoleniae are endosymbionts of diatoms, providing a nitrogen-fixing function. It is assigned by Bergey's to Richelia, which is closely related to this species does not include Calothrix as a genus, opting to instead assign its members to other genera. No genomes of the type species are available.