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Name derivation:

From the latin nodus, dim. nodulus , knotty, nobby, perhaps in reference to the presence of aerotopes (gas vesicles) or akinetes.

Classification:

Nodularia  Mertens ex Bornet and Flahault  1886;  18 of 32 species descriptions are currently accepted taxonomically (Guiry and Guiry 2013).

Order Nostocales;  Family Nostocaceae

 

Morphology:

Single or groups of uniseriate, Unbranched, bipolar, sometimes mobile, sheathed trichomes of discoid cells, with heterocysts that are either intercalary (between vegetative cells) at regular intervals, or terminal, and do not differ from vegetative cells in shape. Akinetes are usually in a series, away from heterocysts, and shorter than wide. Sometimes gas vesicles are present.

 

Similar genera:

Nodularia is similar to Anabaena , but the vegetative cells are discoid and isometric vs. cylindrical in Anabaena.

Death of two dogs after exposure to lakewater in 1990 on the North Sea coast of Germany was likely due to a bloom of Nodularia spumigena (Nehring 1993.

 

Toxicity:

Nodularia spumigena in the Baltic Sea produces a cyclic pentapeptide that is a hepatotoxin, based on intraperitoneal mouse bioassays (Sivonen et al. 1989).

 

Habitat:

Some species are planktonic, usually bearing gas vesicles, and can form massive blooms in reservoirs, rarely in freshwater and more so in brackish water or coastal marshes and lakes. Benthic species never bear gas vesicles and are found in coastal marshes, lakes littoral zone, and rice paddies, where their ability to fix nitrogen is important.

 

References:

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.

Nehring, S.  1993.  Mortality of dogs associated with a mass development of Nodularia spumigena (Cyanophyceae) in a brackish lake at the German North Sea coast.  Journal of Plankton Research 15(7):867-872.

Sivonen, K., K. Kononen, W.W. Carmichael, A.M. Dahlem, K.L. Rinehart, J. Kiviranta and S.I. Niemela.  Occurrence of the hepatotoxic cyanobacterium Nodularia spumigena in the Baltic Sea and structure of the toxin.  Applied and Environmental Microbiology 55(*):1990-1995.