Checklist of the fish fauna of the Munim River Basin, Maranhão, north-eastern Brazil

• DOI: 10.3897/bdj.11.e98632
• Publication Date: 2023-02-10T12:15:32Z
• Authors: Lucas Vieira; Diego Campos; Rafael Oliveira; Josie South; Marcony Coelho; Maurício Paiva; Pedro Bragança; Erick Guimarães; Axel Katz; Pâmella Brito; Jadson Santos; Felipe Ottoni
• Keywords: Characiformes; Characidae; Ecoregion

The Maranhão State harbours great fish diversity, but some areas are still undersampled or little known, such as the Munim River Basin in northeast of State. This lack knowledge is critical when considering anthropogenic impacts on riverine systems especially face major habitat destruction. These pressing threats mean that a comprehensive understanding diversity and checklists extremely relevant. Therefore, present study provides checklist species found Basin, State, north-eastern Brazil, based collected specimens. A total 123 were recorded for with only two non-native species, Oreochromis niloticus Colossoma macropomum , showing assemblage has relatively high ecological integrity. In addition, 29 could not be identified at level, indicating presence probably new to science Basin. predominance belonging orders Characiformes Siluriformes, Characidae being recovered most species-rich family (21 species) agrees general pattern river basins Neotropical Region. was estimated by extensive fieldwork, including several sampling gears, carried out different seasons (dry rainy) exploring environments both daily nocturnal sampling, from Basin's source its mouth. 84 sites sampled between 2010 2022, resulting 12 years fieldwork. Fish assemblages distinct Estuary Upper basin sections more similar Lower Middle environmental filtering processes. Species weakly nested across sections, unique each section (per Simpsons Index). High variability richness likely due microhabitat heterogeneity supporting specialist communities.