Spirulina is a genus of cyanobacteria, not to be confused with the dietary supplement of the same name actually belonging to the genus Arthrospira.
Spirulina is the common name for human and animal food supplements produced primarily from two species of cyanobacteria: Arthrospira platensis, and Arthrospira maxima. These and other Arthrospira species were once classified in the genus Spirulina. There is now agreement that they are distinct genera, and that the food species belong to Arthrospira; nonetheless, the older term "Spirulina" remains the popular name. Spirulina is cultivated around the world, and is used as a human dietary supplement, available in tablet, flake, and powder form. It is also used as a feed supplement in the aquaculture, aquarium, and poultry industries.