REVIEW PAPER Everything is not everywhere: a tale on the biogeography of cyanobacteria Karine Felix Ribeiro . Leandro Duarte . Luciane Oliveira Crossetti Received: 30 January 2018 / Revised: 15 May 2018 / Accepted: 25 May 2018 Ó Springer International Publishing AG, part of Springer Nature 2018 Abstract Microrganisms such as cyanobacteria have been often considered as exhibiting wide distri- bution mainly driven by environmental heterogeneity. Recently, however, new findings have evoked the role of previously neglected processes, such as dispersal limitation, determining the distribution of a wide range of microorganisms, including cyanobacteria. Here, we reviewed the biogeographic patterns of cyanobacteria with focus on molecular data and the evidences from the published literature for the processes driving these patterns. Also, considerations are made about concept of species, discordances in the taxonomic concepts, and level of taxonomic resolu- tion, and how these affect the biogeographic study of cyanobacteria. From a overview, it can be observed that both environmental and historical factors are important to structure cyanobacteria diversity across time and space. Moreover, different species may exhibit significant differences in their distribution patterns, from possibly cosmopolitan species to other endemic species. However, distribution patterns are closely dependent on the concept of species, besides the taxonomic resolution, spatial and environmental scales, and the biases of the molecular methodologies applied in the studies. Thus, efforts to broaden sampling and sequencing of unknown and less-known species, as well as geographic regions and habitats poorly exploited, are crucial for a better understanding of cyanobacteria biogeography. Keywords Microbial cosmopolitanism Á Microbial diversity predictors Á Phylogeography Á Microbial ecology Á Cyanoprokaryota Introduction Cyanobacteria are a diverse group of microrganisms characterized as being oxygenic photosynthetic bac- teria that possess chlorophyll a (Castenholz, 2001). Cyanobacteria possess a high ecological plasticity, thanks to which they occur in varied, often even extreme, habitats (Whitton & Potts, 2000). This group was responsible for critical events throughout the evolutionary history of life on Earth, such as the history of Earth-surface oxygenation (Lyons et al., 2014; Rasmussen et al., 2008; Sessions et al., 2009) and the evolution of eukaryotic cell through Handling editor: Judit Padisa ´k K. F. Ribeiro (&) Á L. Duarte Á L. O. Crossetti Programa de Po ´s-Graduac ¸a ˜o em Ecologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonc ¸alves, 9500. Setor 4 - Pre ´dio 43422, sala 105, Porto Alegre, RS 91540-000, Brazil e-mail: kafelixribeiro@gmail.com L. Duarte Á L. O. Crossetti Departamento de Ecologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91540-000, Brazil 123 Hydrobiologia https://doi.org/10.1007/s10750-018-3669-x