Testing the prey naiveté hypothesis: Can native prey (Astyanax ruberrimus) recognize an introduced top predator, Cichla monoculus?

• Published in: Biological invasions Vol. 23; no. 1; pp. 205 - 219
• Main Authors: Sharpe, D. M. T., de Lira, J. J. P. R., Brown, G. E., Torchin, M. E., Hendry, A. P.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2021; Springer Nature B.V
• Subjects: Anti-predator behavior; Astyanax ruberrimus; Biomedical and Life Sciences; Chemical stimuli; Cichla monoculus; Conspecifics; Developmental Biology; Ecology; Exposure; Fish; Freshwater & Marine Ecology; Hypotheses; Life Sciences; Original Paper; Plant Sciences; Predators; Prey; Biological invasions; Anti-predator behaviour; Chemical cues; Peacock bass; Prey naiveté; Predator–prey interactions
• ISSN: 1387-3547; 1573-1464
• DOI: 10.1007/s10530-020-02369-4

The prey naiveté hypothesis (PNH) posits that prey will often fail to recognize and respond to introduced predators with whom they do not share a co-evolutionary history. We tested this hypothesis by examining anti-predator behaviour in the native characid fish Astyanax ruberrimus in response to its main native ( Hoplias microlepis ) and introduced ( Cichla monoculus ) fish predators in Panama. We observed the behaviour of wild-caught A. ruberrimus from an invaded and uninvaded site following exposure to chemical stimuli from: (1) injured conspecifics, (2) the native predator, and (3) the introduced predator. We found, first, that A. ruberrimus consistently responded to cues from injured conspecifics, suggesting that this species possesses an alarm signaling mechanism similar to that observed across Ostariophysan fishes. Second, A. ruberrimus responded to cues from their native predator, but only in one population, suggesting responses may be threat-sensitive. Third, A. ruberrimus lacking prior exposure to C. monoculus did not respond to cues from this predator, consistent with the PNH. In contrast, A. ruberrimus that have co-occurred with C. monoculus for several decades did respond to cues from this predator, suggesting that prior exposure to C. monoculus has led (either via local adaptation or learning) to acquired predator recognition. Overall, our findings are consistent with the PNH, although we cannot conclusively rule out alternate explanations for the observed differences between populations. Our work represents a first step towards understanding the role that behavioural naiveté may have played in the initial stages of this important tropical freshwater introduction.