Prey naiveté is proposed as one of the main reasons behind species extinctions attributed to invasive predators. This study examined whether the naiveté hypothesis could explain extinctions after the introduction of peacock bass (Cichla kelberi) in Paraná River, Brazil. Our results show that prey responded to both visual and chemical cues of peacock bass. Displayed avoidance behaviors were equal to or greater than those observed with a native predator, Hoplias malabaricus. We conclude that lack of recognition was not responsible for the observed vulnerability of native species to this introduced predator. Finally, we discuss implications of these findings for the native biodiversity and convene other potential explanations for the observed effects of peacock bass on native prey.
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Acknowledgments We are very thankful to the Núcleo de Pesquisas em Limnologia, Ictiologia e Aquicultura/ Universidade Estadual de Maringá and CNPq for supporting this study. Travel to Brazil was supported by the USDA Invasive Species Collaboration Program (to KK and ED). Sidinei Thomaz played a pivotal role in helping this study materialize. And we are especially grateful to Sebastião Rodrigues for his help with setting up the experiment and collecting the fish. We also thank Sidinei Thomaz, Gary Ervin and two anonymous reviewers for their helpful comments on this manuscript.
- Antipredator behavior
- Chemical cue
- Non-native species
- Predator avoidance
- Prey naiveté