Testate amoebae (Arcellinida and Euglyphida) from the state of Bahia: a synthesis of 108 years of scientific discoveries and contributions.

Abstract

Testate amoebae are widely distributed organisms, playing essential roles in several aquatic and terrestrial ecosystems. This study presents an overview of the biodiversity of Testate amoebae (Arcellinida and Euglyphida) in the state of Bahia, Brazil, over the last 108 years, based on unpublished data and information from the literature. The records covered 19 municipalities and seven river basins. A total of 172 infrageneric <italic>taxa</italic> were identified, with Difflugiidae and Arcellidae standing out as the most representative and <italic>Centropyxis aculeata</italic> as the only constant species (FO = 100%). We observed a total of 25 occurrences that were new to the state. The study considered ecological and methodological aspects, including biomes, types of aquatic bodies, ecosystems, collection methods, mesh sizes, and compartments. Methods such as washing macrophyte rhizospheres and using 20 μm nets have demonstrated greater efficiency in estimating richness. The analysis of accumulation curves indicated that the sampling method recorded approximately 76.3% of the estimated biodiversity. Despite the advances, gaps remain, <italic>e.g.,</italic> in the Cerrado biome, in temporary lakes, and in sediments. This study reinforces the importance of methodological standardization and investment in studies in the Bahia state to improve knowledge about regional and global biodiversity.