A New Potential Invader: First Record of the Pirambeba Serrasalmus geryi (Characiformes: Serrasalmidae) in the upper Paraná River floodplain, Brazil

Abstract

Detecting a potentially invasive introduced species is crucial for efficient conservation strategies. We recorded the first occurrences of the “pirambeba” Serrasalmus geryi in the upper Parana River floodplain, Brazil, in December 2019. A long-term ecological research program (PELD site 6) has been monitoring the region since 1986. One specimen was collected in the Itaipu Reservoir (106.2 mm standard length (SL)) and two other in the Ivinhema River, a tributary of Parana River (167.1–183.0 mm SL). Previous studies have reported an agonistic interaction between two syntopic congeners in the upper Parana River floodplain, namely S. maculatus (native) and S. marginatus (invasive), with resulting decrease in the abundance of the native species. Here, we warn that the introduction of S. geryi may act in synergism, aggravating this trend, although little is known about the behavior of S. geryi.