Generic name: ARTHROSPIRA Stitzenberger ex Gomont, 1892. Ann. Sci. Nat. Bot., ser. 7, 16: 246.
Synonyms: ARTHROSPIRA Stitzenberger, Spirulina und Arthrospira, in Hedwigia, I, p. 32, 1852 ex Gomont, 1892;
Spirillum, Spirulina, Arthrospira
Trichomala cylindracea, evaginata, in spiram eximie regularem plus minusve laxam contorta, apice aequalia aut attenuata; cellula apicalis superne rotundata; calyptra nulla.
Type species: Arthrospira jenneri Stizenberger ex Gomont 1892

Komárek (1992): Filamentous; filaments unbranched, solitary and free living (floating), or in mats which are microscopic or macroscopic, covering the substrate,
more or less regularly screw-like and more or less freely coiled along the whole length, with unchanged or continually changing (decreasing or increasing) width of screws; trichomes:spirals width ratio = (2.5)-5-(10).
Sheaths usually missing, rarely facultatively developed, colourless, tube-like, joined to trichomes, opened at the ends, containing always only one trichome. Trichomes isopolar, 3-10 jum wide, uniserial, composed from cylindrical cells, constricted br unconstricted at the visible cross walls, not attenuated or slightly attenuated towards the ends, motile (rotation). Cells without aerotopes or (in planktic species) with aerotopes, more or less isodiametric or shorter than wide, sometimes granular and with condensed granules at the cross walls; end cells widely rounded and usually with thickened outer cell walls or with calyptras (in developed trichomes); special perforation of cell walls (cross walls and side walls; see in Guglielmi et Cohen-Bazire 1982; all species?). Cell content pale or bright blue-green or olive green; thylakoids situated perpendicularly and irregularly along the cell walls. Heterocytes and akinetes missing.
Genotype differences, molecular data:
Reproduction strategies, life cycles, cell division:
Komárek (1992):Cell division cross-wise, perpendicularly to the long axis of a trichome, daughter cells grow more or less to the original size before the next division. All cells capable to divide with the exception of apical ones. Reproduction by fragmentation of trichomes into motile hormogonia, which separate by help of necridic cells.
Taxonomic position, higher hierarchy: Cyanophyceae,
Oscillatoriales, Phormidiaceae, Phormidioideae
Notes to taxonomy, misinterpretations:
Ecology, ecophysiology, ecological

Komárek (1992): Several species are benthic in freshwater biotopes ( A. jenneri, A. platensis, etc.), several are planktic, mainly in tropical and salinic (mineral) lakes and water reservoirs (A. maxima , A. fusiformis), and used as important biotechnological organisms for mass culture (usually under the
incorrect name "Spirulina platensis" ). Few species are known from marine littoral biotopes (A. funiformis ).
Gomont (1892): Plantae hydrophilae aut halophilae, nunquam terrestres.
Physiology and biochemistry:
Distribution, endemism, problematic citations:
Reference strain:
Infrageneric scheme, species concept:
List of species: species:
types without gas-vesicules (forming mats)
Arthrospira balkrishnaii Kamat 1963
Arthrospira desikacharyensis Vasishta 1962
Arthrospira gigantea (Schmidle) Anagnostidis 1998
Arthrospira gomontiana Setchell 1895
Arthrospira jenneri Stizenberger ex Gomont 1892, Ann. Sci. Nat. Bot., ser. 7, 16: 247
Arthrospira masartii Kufferath 1914
Arthrospira pellucidis Wang 1933
Arthrospira platensis (Nordstedt) Gomont 1892, Ann. Sci. Nat. Bot., ser. 7, 16: 247
Arthrospira santannae Komárek et Komárková-Legnerová 2006
Arthrospira skujae Magrin et al. 1998
Arthrospira tenuis Brühl et Biswas 1922

types with gas-vesicules (planktic, solitary trichoms)
Arthrospira argentina (Frenguelli) Guarrera et Kühnemann 1949
Arthrospira fusiformis (Voronichin) Komárek et Lund 1990
Arthrospira ghannae Drouet et Strickland in Drouet 1942
Arthrospira indica Desikachary et Jeeji Bai 1992
Arthrospira joshii Vasishta 1963
Arthrospira maxima Setchell et Gardner in Gardner 1917

Unclear taxa:
Arthrospira amethystina (Buell) de Toni 1949
Arthrospira ardissonii (Cohn) Forti 1907
Arthrospira margaritae Gomont ex Frémy 1927
Arthrospira miniata
Gomont ex Gomont 1892, Ann. Sci. Nat. Bot., ser. 7, 16: 248
Oscillatoria spirulinoides Voronichin 1932
Spirulina aeruginea Buell 1938
Spirulina allansonii Welsh 1961
Spirulina attenuata Umezaki 1952
Spirulina cabrerae Gonzalez Guerrero 1946
Spirulina cavanillesiana Gonzalez Guerrero 1946
Spirulina erdosensis Tian et al. 2002
Spirulina gordiana Gonzalez Guerrero 1946
Spirulina mariae Margalef 1953

List of stains:
Application technology:
Drawings: Komárek
  2.1 taxonomy: Gomont 1892, Geitler 1932, Geitler 1942, Fott et Karim 1973, Compere 1974, Guglielmi & Cohen-Bazire 1982, Hindák 1985, Jeeji-Bai 1985, Anagnostidis & Komárek 1988, Komárek 1989, Komárek & Lund 1990.
  2.2 cytomorphology:
  2.3 16S rRNA sequencing:
  2.4 biology and life cycles:
  2.5 ecology: