Data collection
To test the hypotheses, we used a database composed of 76 streams of three distinct hydrographic regions of Brazil: (i) Araguaia-Tocantins; (ii) Paraná; and (iii) São Francisco, with all streams located within the Cerrado biome (Fig 1) and can be accessed in Vieira et al. (2020). All sampled streams are first- to third-order, georeferenced; the ichthyofauna was sampled by trawl or electric fishing at least along 50 m of the channel. The local environmental conditions measured were turbidity, conductivity, pH, dissolved oxygen, water velocity, width and depth channel (three measurements in each stream).
Fig 1. Location of the 76 sampled streams (points) in the three hydrographic regions considered of the Brazilian Cerrado biome.