About endemism of cyanobacteria in freshwater habitats of maritime Antarctica
Cyanobacteria were once considered as cosmopolitan and ubiquitous organisms, occurring also in Antarctic ecosystems. They were identified therefore mostly according to European and North American determination keys (cf. Geitler 1932, Prescott 1979). However, recent molecular analyses and precise morphological and ecological characterizations found that special cyanobacterial communities develop in freshwater habitats of Western Antarctica every year. They contain taxonomically unique genotypes (OTUs) delimited for habitats of coastal and deglaciated Antarctica. These studies indicate that, at least, several Antarctic important species of cyanobacteria (in modern, revised concept) are endemic or restricted only for polar habitats. This statement corresponds with other extreme ecosystems over the world.