Differential use of artificial habitats by native and non-native fish species in Neotropical reservoirs

Abstract

The use of artificial habitats as tool for management and conservation of lentic freshwater ecosystems has been most studied in North America, with dominance of Centrarchidae fish. Contrary to north temperate ecosystems, Cichlidae species appear to be prevalent on artificial habitats in Neotropical reservoirs. Currently, due to the rapid expansion of non-native fish introductions globally, these two fish families are increasingly expected to coexist in the same environments. This study aimed to test experimentally the use of artificial habitats by fish in two Neotropical reservoirs between: (i) kind of habitats, (ii) Cichlidae and Centrarchidae, (iii) native and non-native species, and (iv) size classes. The results showed a higher number of individuals and species in pipes and rocks habitats. The dominance of Cichlidae over Centrarchidae in pipes, rocks and control habitats suggests a kind of partitioning between these groups. Native Cichlidae (< 80 mm) were predominant in pipes whereas native and non-native species seemed to share tree and rock habitats. Artificial habitats can potentially increase local abundance and diversity of fish species, however, it is essential to consider the species’ origin (i.e. native or non-native) associated with each kind of artificial habitat in order to prevent invasive species from benefiting of artificial structures deployment in freshwater systems.