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Name derivation:

"Bluegreen cell" Bluegreen Glauco- cell cystis

Classification:

Glaucocystis Itzigsohn in Rabenhorst 1866; 7 of 14 species descriptions are currently accepted taxonomically (Guiry and Guiry 2013).

Order Glaucocystales; Family Glaucocystaceae

Morphology:

Often four ovoid or egg-shaped cells within an outer membrane. Each cell appears to contain several cyan procaryotic cyanelles. The outer host membrane is thought to be chlorophycean. The overall appearance resembles the arrangement of cells in Oocystis, as if the chlorophycean chloroplasts have been replaced by cyanobacteria. Some authors consider the Glaucophyceae to be in Class Chlorophyceae, Order Chlorococcales, Family Oocystaceae -- even though the cyanelles cannot have been derived from a green eucaryote. For example, see online. Elsewhere the cyanelle has been named Skujapelta nuda nov. gen., nov. sp.; in a new family Skujapeltaceae in the order Chroococcales of the Chlorophyceae (Hall and Claus 1967).

Development of the cellulosic cell wall starts as a thin nonfibrillar layer on which cellulosic microfibrils form in helically crossed polylamellate fashion. Finally matrix substances are deposited. There are twelve helically wound wall layers (Willison and Brown 2012).

Because the wall structure is similar to that of the chlorophycean genera Oocystis and Valonia (Ibid. 2012), it is apparent that Glaucocystis, and by extension other glaucophyceae, are colorless chlorophycean hosts of photosynthetic cyanobacterial endobionts.

Similar genera:

 

 

Habitat:

Freshwater, usually found in shallow lakes epiphytic on aquatic macrophytes.

 

 

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 10 September 2013.

Hall, W.T., and G. Claus 1967. Ultrastructural studies on the cyanelles of Glaucocystis nostochinearum Itzigsohn. J. Phycol. 3:37-51.

Willison, J.H.M. and R.M. Brown Jr. 1978. Cell wall structure and deposition in Glaucocystis. J. Cell Biology 77(1):103-19.