Chroococcus turgidus

Fig. 2.1 Chroococcus turgidus, a species of cyanobacteria, which are prolific producers of organohalogens (Photo A. D. Wright)...

Peat-bog waters have a great Insufficiency of calcium, they are strongly acidic and contain mostly humic substances and carbonic acids. In such waters, algae (Desmidiaceae), less frequently cyanobacteria Chroococcus turgidus) and protozoa Rhizopoda) can be found. 

While hsh kills have occurred during cyanobacterial blooms, the direct link between mortalities in hshponds and cyanotoxins has been elusive, because fish kills can often be explained by low levels of dissolved oxygen or increases in ammonia concentration when the bloom crashes (Seymour, 1980 Sevrin-Reyssac and Pletikosic, 1990). For example, recently in a Japanese shrimp farm, a bloom of Chroococcus turgidus was associated with mass mortalities of farm-raised Penaeus japonicus, but the direct cause was the increase in pH of pond water (Momoyama, 2004). 

Momoyama, K. Mortalities of farm-raised kuruma prawn Penaeus japonicus caused by high pH ambient water due to blooms of a blue-green alga, Chroococcus turgidus. Fish Pathol., 39(3), 129, 2004. 

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