Ecology of habitat choice by Macrobrachium brasiliense (Heller, 1862) (Crustacea, Decapoda, Palaemonidae) on different substrates and microhabitats

The main objective of this study was to analyze the choice behavior of adult individuals of Macrobrachium brasiliense (Decapoda, Palaemonidae) with regard to different substrates and microhabitats in two distinct experiments. The first experiment offered the prawns three samples of substrates with different granulometries: fine sand, coarse sand, and gravel. The second experiment offered three types of microhabitats: aquatic macrophytes, wood fragments, and rocks. In general, the prawns chose the fine substrate, to a significant extent (ANOVA, p 0.01). In the microhabitat experiment, the prawns selected the wood fragments (ANOVA, p 0.01). In general, these results show that substrates with fine sand and microhabitats composed of fragments of wood might provide direct benefits for M. brasiliense, such as protection against predators and food availability through biofilm formation.The main objective of this study was to analyze the behavior of adult individuals of Macrobrachium brasiliense and their preferences regarding different substrates and microhabitats. The study comprised two distinct experiments; selection of substrates (1) and microhabitats (2). The first one was performed using three samples of substrates with different granulometries: fine sand, coarse sand and gravel. After, the microhabitat selection experiments were carried out using three types of microhabitats: algae, fragments of wood and rocks. There was a significant difference in males substrate preference (ANOVA, p 0.01), which preferred fine substrate. For females, there was no significant difference in preference for any of the three substrates (ANOVA, p 0.05). Regarding microhabitats, only algae were not selected by males (ANOVA, p 0.01), whereas females chose only the microhabitat composed of wood fragment (ANOVA, p 0.01). Based on these results, the existence of a differential behavior between the sexes for selection of substrates and microhabitats, suggesting that these animals can inhabit different places in the same environment, since in the laboratory a differentiation in their choices was observed