Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju, an expanding, highly adaptive cyanobacterium : worldwide distribution and review of its ecology

Because of this potential toxicity and tendency to form dense blooms that interfere with different kinds of water use, Cylindrospermopsis raciborskii has become one of the most notorious blue-green algal species. Its ecological success is attributable to many factors like buoyancy, tolerance of low light, ability to use internal P-sources, high affinity P- and ammonia uptake, N (2)-fixation and resistance to grazing by zooplankton. Existing information about the above factors are discussed. C. raciborskii can successfully travel along river courses and, moreover, especially in subtropical temperate lakes, it produces large numbers of resistant akinetes, suitable to dispersal by birds and other chance events. It survives swampy or slightly saline conditions. These make the species a successful invader: during the 20th century it has apparently spread to more and more water bodies all over the world which represent a wide habitat diversity. An analysis of ecological constraints, available floristic data and migrational patterns leads to a hypothesis concerning the origin and the present distribution. Investigations on genetic, biochemical and ecophysiological level in cultured materials deriving from different areas of the world are desirable.