Distribution of Boulengerella cuvieri and B. lucius (Characiformes, Ctenoluciidae) on eastern Brazilian Amazon: updating records and discussing conservation status

Through field sampling and examination of scientific collections, this study provides new records and confirms the occurrence of Boulengerella cuvieri and B. lucius in the eastern Brazilian Amazon, northern Brazil. The occurrence of Boulengerella lucius for the Guamá River basin is here confirmed, specifically on its upper portion. The occurence of Boulengerella cuvieri is confirmed for: Guamá River basin, Pará state; Gurupi River basin, on the border between Pará and Maranhão states; and the Turiaçu River basin, in the eastern part of Maranhão state. Additionally, photographs and updated data on the distribution, conservation, taxonomy, and morphology of these two species are provided here. The results emphasize the importance of continuous database curation, especially regarding regions that are underrepresented in the scientific literature. Regarding to the species conservation status, a review and improvement of the assessment criteria is here proposed and applied, revealing a scenario worse than previously conceived.