Conservation status of the freshwater fish species from Ceará State, Brazil

Abstract Red Lists, which assess species’ extinction risk, are essential in formulating public policies for natural resources management and impact mitigation. The objective of this study was to characterize the conservation status of the continental ichthyofauna of the State of Ceará, based on ichthyological occurrence data and criteria from the International Union for Conservation of Nature. Eighty-five fish species belonging to 59 genera, 25 families, and eight orders were recorded in Ceará. Forty-three species were considered Least Concern, four Near Threatened, 17 were threatened, 15 were Data Deficient, and six species were not evaluated. Among the 17 species considered threatened, five were classified as Vulnerable, five as Endangered, and seven as Critically Endangered. The Metropolitan and Salgado basins presented the highest richness (44 and 39 species, respectively). In contrast, the Serra de Ibiapaba (6) and Curu (17) basins had the lowest richness, indicating wide variability among the evaluated basins. The basins with the highest relative number of threatened fish species were the Metropolitan, Litoral, and lower Jaguaribe basins. These findings highlight the urgent need for targeted conservation actions to safeguard the freshwater fish diversity in Ceará, particularly in the basins with the highest number of threatened species.