Multiple predator effects and native prey responses to two non-native Everglades cichlids

Authors

Ashley E. Porter-Whitaker, Oceanographic Center, Nova Southeastern University
Jennifer S. Rehage, Earth and Environment Department, Southeast Environmental Research Center, Florida International UniversityFollow
Shawn E. Liston, Audubon of Florida, Corkscrew Swamp SanctuaryFollow
William F. Loftus, Aquatic Research & CommunicationFollow

Abstract

Non-native predators may have negative impacts on native communities, and these effects may be dependent on interactions among multiple non-native predators. Sequential invasions by predators can enhance risk for native prey. Prey have a limited ability to respond to multiple threats since appropriate responses may conflict, and interactions with recent invaders may be novel. We examined predator–prey interactions among two non-native predators, a recent invader, the African jewelfish, and the longer-established Mayan cichlid, and a native Florida Everglades prey assemblage. Using field enclosures and laboratory aquaria, we compared predatory effects and antipredator responses across five prey taxa. Total predation rates were higher for Mayan cichlids, which also targeted more prey types. The cichlid invaders had similar microhabitat use, but varied in foraging styles, with African jewelfish being more active. The three prey species that experienced predation were those that overlapped in habitat use with predators. Flagfish were consumed by both predators, while riverine grass shrimp and bluefin killifish were eaten only by Mayan cichlids. In mixed predator treatments, we saw no evidence of emergent effects, since interactions between the two cichlid predators were low. Prey responded to predator threats by altering activity but not vertical distribution. Results suggest that prey vulnerability is affected by activity and habitat domain overlap with predators and may be lower to newly invading predators, perhaps due to novelty in the interaction.

Comments

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Porter-Whitaker, A.E., J.S. Rehage, S.E. Liston, W.F. Loftus. 2012. Multiple predator effects and native prey responses to two non-native Everglades cichlids. Ecology of Freshwater Fish 21(3): 375-385.