Prokaryotní sinice a řasy svým významem a rozšířením patří mezi hlavní složky současné antarktické vegetace. Jsou schopny neobyčejně rychlého startu vegetace, rychlého namnožení velké biomasy a okamžitého přechodu do klidových stadií, která snášejí i velmi nízké teploty po dlouhou dobu. Jsou proto velmi hojné na všech stanovištích, kde se alespoň po krátké období během roku vyskytuje voda v tekutém stavu. and Prokaryot blue-green algae and algae are among the major components of Antarctic vegetation due to their importance and wide distribution. They can very rapidly start their growing period, produce a great amount of biomass and pass immediately into dormancy, during which they can survive very low temperatures for a long period. For this reason they are very frequent in localities with water in liquid form for at least a short period of the year.
Two differently coloured strains of the genus Chroococcus were isolated from a cyanobacterial assemblage collected from the stony littoral of a backwater of the Danube River in southern Slovakia. When grown after isolation, both subcultures were similar morphologically and their growth parameters did not differ substantially, but their pigment content (PC: PE and carotenoid ratios), details in their morphology during their life cycles and slime production were different. Identical and different characters of both morphotypes remained stable during cultivation on both agarized and liquid media, even when the cultivation parameters were changed. Both of the subcultures were studied using electron microscopy and almost their complete 16S rRNA genes were sequenced, which showed that in terms of their genetic relationship there was a 96.4% sequence similarity and certain taxonomic interspecific differences between both subcultures were confirmed. The various chromatic modifications recorded in cyanobacteria and their ecological consequences are discussed. The results yielded further data on the changes that occur during the cyanobacterial differentiation processes and their genetic stabilization.
Nineteen traditional Anabaena morphospecies were found in freshwater habitats in Cuba. Their taxonomic identification is discussed and variation in natural populations described. Seven species are known only from tropical countries (A. ambigua, A. fuellebornii, A. iyengarii, A. oblonga, A. orientalis, A. recta, A. volzii), four from tropical America (A. manguinii, A. portoricensis, A. torques-reginae, A. unispora), one was originally described from southern Africa (A. austro-africana) and one from central Asia (A. turkestanica). Two taxa are recognized as new species (A. hatueyi, A. jeejiae) and two remain unidentified (Anabaena spp.) because of a shortage of material. Only two species, A. cf. reniformis and A. cf. bornetiana, may occur also in the temperate zone (Europe or North America) and as special morphotypes in Cuba.
Two new species of the genus Camptylonemopsis (Cyanoprokaryota, Cyanobacteria), namely C. epibryos spec. nova and C. sennae spec. nova, are described from the coastal tropical rainy forest “Mata Atlantica” in Brazil (state Săo Paulo). The diacritical features and the taxonomic position of the genus, particularly the comparison with the related genera Coleodesmium, Tolypothrix and Scytonema are discussed. The tabular review of the genus Camptylonemopsis is presented.