Assessment of predator naïveté for an insular fish species: the White Sands pupfish, Cyprinodon tularosa

Authors: Molly Johnson, Brian Wisenden, Craig Stockwell

Year: 2023

Abstract

The predator naïveté hypothesis predicts that native prey that evolved with limited predation pressure will lack antipredator responses to non-native predators due to a lack of shared co-evolutionary history. Impacts of non-native predators on isolated desert fish populations have been attributed to predator naïveté. For example, Pahrump poolfish, Empetrichthys latos, were incapable of recognizing and responding to conspecific alarm cues, which may explain the high vulnerability of poolfish to invasive predators. Like the Pahrump poolfish, the White Sands pupfish, Cyprinodon tularosa, evolved in the absence of fish predators and have been isolated in the Tularosa Basin for approximately 2.5 million years. Testing C. tularosa to the predator naïveté hypothesis with conspecific alarm cue can shed light on their potential to detect and avoid invasive predators. In this study, we examined the behavioral responses of female C. tularosa to conspecific alarm cues in terms of fish activity and water column position. Pupfish reduced activity and moved to lower position in the water column in response to conspecific alarm cues. These antipredator behavioral responses are consistent with recent findings for several other pupfish species and suggest that C. tularosa have retained antipredator behaviors, despite a long period of isolation from fish predators.