Implications of using a variety of fishing strategies and sampling techniques across different biotopes to determine fish species composition and diversity

The objective of this study was to evaluate the combination of some sampling gears operated in different biotopes on fish species richness and species composition. Fish were collected from five different types of biotopes in the Upper Parana River floodplain, according to the most suitable sampling gear for the characteristics of each biotope. A total of 116 fish species were identified in the samples and the highest species richness (68 species) was recorded in streams sampled with boat electrofishing. Rivers and open lakes sampled with gillnets showed the greater similarity between the biotopes, while creeks sampled with electrofishing and open lakes sampled with gillnets showed the least. There were significant differences in species composition among the combinations of biotopes/fishing gears. The results of this study demonstrate the importance of using a variety of fishing methods to sample the different biotopes within a region. We emphasize the importance of well-conducted inventories that take into account the particularities of individual environments.