Home / Cyanobacteria / Filaments / Unbranched / Tapered / Calothrix
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Name derivation:
From the Greek kalos, beautiful, and thrix, the hair
Classification:
Calothrix C.Agardh ex Bornet and Flahault 1886; 93 of 156 species descriptions are currently accepted taxonomically (Guiry and Guiry 2013). Order Nostocales; Family Rivulariaceae
Morphology:
Attached trichomes larger at the base and tapering, each with a basal heterocyst.  False branching may occur when a separate trichome forms inside its own sheath. Trichomes may occur singly or arranged in parallel in groups but single trichomes always separate.
Similar genera:
Habitat:
Freshwater and marine (Sihvonen et al. 2007), on plants and hard substrata. Some species occur in the marine intertidal zone.
References:
Bornet, É. and C. Flahault 1886. Revision des Nostocacées hétérocystées contenues dans les principaux herbiers de France. Annales des Sciences Naturelles, Botanique, Septième série 3: 323-381. Guiry, M.D. and G.M. Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 04 September 2013. Sihvonen, L.M., C. Lyra, D.P. Fewer, P. Rananiemi-Wacklin, J.M. Lehtimaki, M. Wahlsten and K. Sivonen 2007. Strains of the cyanobacterial genera Calothrix and Rivularia isolated from the Baltic Sea display cryptic diversity and are distantly related to Gloeotrichia and Tolypothrix. FEMS (Fereration of European Microbiological Societies) Microbiological Ecology 61:74-84.