Invasibility of reservoirs in the Paraná Basin, Brazil, to Cichla kelberi Kullander and Ferreira, 2006

The invasion process comprises not only the characteristics of nonindigenous species but also the attributes of the invaded environment which make it susceptible to the establishment of nonindigenous species. Habitat attributes operate like filters in determining the establishment of introduced species and the invasibility of a region. In the Upper Parana River Basin, Brazil, the practice of introducing species was quite common and frequently carried out by hydroelectric companies. The target species of the present study, the peacock-bass Cichla kelberi, is native to the Amazon Basin. This species was introduced into several reservoirs of the Upper Parana River Basin and is dispersing rapidly throughout the system. This study shows which characteristics of the reservoirs facilitate their invasibility after testing for the effect of propagule pressure. We conclude that a set of abiotic factors favors the invasibility of these reservoirs. To be more precise, the largest, deepest, most transparent and warmest reservoirs are the most likely to be colonized by Cichla kelberi. It is possible that other environments with similar characteristics to these reservoirs, such as the lagoons from the Upper Parana River Basin floodplain, can also be colonized by Cichla kelberi.