The genus Arthrospira includes filamentous cyanobacteria with multicellular cylindrical trichomes arranged in an open helix. The biomass of Arthrospira is composed of protein (50-70%), carbohydrates, lipids and minerals. It also contains carotenoids, phycocyanin and vitamins. Arthrospira species are found in tropical and semitropical regions. Arthrospira is industrially cultivated because of its high nutritional values as well as of its therapeutic properties. Commercial production of Arthrospira is carried out in open ponds and closed bioreactors. The biomass is sold by the incorrect name ?Spirulina' as a result of confusion in nomenclature regarding the genus Arthrospira.