Exploring Blind Spots in Amazonian Anuran Diversity: An Assessment of Research and Conservation Needs

ABSTRACT The Amazonian megadiversity remains understudied and underestimated due to the region’s vast size, environmental heterogeneity, and inaccessibility. With increasing threats to the biome, it is crucial to map current knowledge before it is lost. This study addresses Linnean (species description), Wallacean (species distribution), and Darwinian (genetic knowledge) shortfalls for Amazonian anurans, quantifying what remains unknown. We reviewed species descriptions, analyzed occurrence data, and evaluated available genetic sequences and phylogenetic uncertainty. Species descriptions have grown over time, peaking around 2000. We estimate that 1,525 species exist in Amazonia, but only 766 (based in the species shapefiles) or 810 (based in the occurrence data) were found. Richness was highest in northern and western Amazonia, while remote areas far from urban centers remain undersampled. Only two genes (mitochondrial 12S and 16S) have been sequenced for more than half of the known species and are available in open databases, while phylogenetic uncertainty predominates in most clades. Regions such as Gurupa Várzea and Cordillera Central Paramo are especially under-sampled. Our results show that taxonomic, distribution, and genetic shortfalls are complementary rather than overlapping, indicating that different regions and species groups require different research strategies. This study highlights major knowledge gaps and provides a framework to guide future efforts in taxonomy, biogeography, and evolutionary studies of Amazonian anurans, supporting conservation planning in one of the most diverse regions on Earth for one of the most diverse and threatened taxonomic groups.