Ichthyofauna in an ecological station in the Pantanal of Brazil: the hydrological cycle affecting species composition

This research aims to describe the ichthyological fauna in the area surrounding the Taiam? Ecological Station in the state of Mato Grosso, Brazil. Three expeditions were carried out, in September 2014, February 2015 and May/2015, in seasons ranging from the hydrological conditions of high waters (flood), low waters (drought), and decreasing waters (ebbing). During the research we sampled 3,664 individuals from six orders, 28 families and 78 species. Characiformes was the most abundant order (? 81 % of individuals), followed by Siluriformes (? 13 % of individuals), and Gymnotiformes (? 4 % of individuals). The most representative species were Moenkhausia dichroura (Kner, 1858), Serrapinus calliurus (Boulenger, 1900), Odontostilbe pequira (Steindachner, 1882) and Pimelodella gracilis (Valenciennes, 1840). The dry period showed the highest abundance (1541 individuals), richness (61 species), diversity (H? = 2.69) and equitability (J? = 0.65). These results fill a gap concerning species composition in the Pantanal, mainly referring to data available on Conservation Unit, and its surroundings. Moreover, this research provides a database to update the checklist of fish species in a remote wetland, offering a tool for management and conservation.