177 years of diatom studies in Brazil: knowledge, gaps, and perspectives.

The actual status of the progress and the main aspects of diatom studies in Brazil remain unknown. This paper describes a survey of published studies addressing material of Brazilian origin in non-marine aquatic environments. Our objectives are to (1) summarize and categorize diatom research topics, (2) to describe how related studies evolved and developed over time, as well as respective journals, (3) to identify the most studied regions and environments, and (4) to indicate the main institutions and works addressing diatom research and related interactions.