The occurrence of non-native species poses a threat to biodiversity and natural ecosystems worldwide. In particular, non-native predators have the potential to negatively impact myriad native taxa in lower trophic levels. In the Greater Everglades ecosystem, fourteen predominantly predatory fishes have invaded and proliferated within the past forty years. Due to the threat these species pose to the native environment, there is a growing need for a better understanding of how these non-native predators interact with native Everglades prey and for an examination of the role behavior may play in mediating these interactions. Behavioral plasticity may allow prey to respond adaptively to non-native predators, with which they have no common evolutionary history. Thus, behavior may play a key role in promoting the survivorship of prey under a novel predation threat.
This study will examine behavioral interactions between non-native predators and native prey by comparing the antipredator responses of three focal prey species: mosquitofish Gambusia holbrooki, flagfish Jordanella floridae, and grass shrimp Palaemonetes paludosus, to the native predator warmouth Lepomis gulosus and to a relatively new non-native predator, the African jewelfish Hemichromis letourneuxi (See Appendix A). These responses will be examined in three experiments, including two experiments that will examine cue recognition by native prey involving visual and chemical cues.
The objective of these experiments is to examine the preyís ability to detect and respond to the novel predator, H. letourneuxi. By gaining a better understanding of preyís response to a non-native predator, new insights can be obtained in the nature of predator-prey interactions when predators are novel. This information will help us understand the potential impact of the non-native species on Everglades aquatic communities and will assist in the management of non-indigenous species within Everglades National Park (ENP).