Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

The great escape: Daphnia pulicaria from post-Bythotrephes invasion time periods have an enhanced escape ability.

Abstract

Non-native species introductions are becoming increasingly common, but long-term consequences of the introduction of non-native predators on native prey species remains poorly understood. Bythotrephes cederströmii is an invasive zooplanktivore with potential negative impacts on Daphnia across North America. However, Daphnia may be responding to this invader by developing anti-predator defenses. We investigated whether escape ability of three Daphnia species (D. ambigua, D. mendotae, and D. pulicaria) differed in the absence and presence of Bythotrephes chemical cues, whether the escape ability of pre- and post- invasion clones of each Daphnia species differed, and whether the three Daphnia species differed in their escape ability. We conducted a series of transfer experiments in the presence and absence of Bythotrephes chemical cues to evaluate the escape ability of the three Daphnia species from both pre- and post-Bythotrephes invasion time periods. Comparison of Daphnia from pre- and post-invasion time periods revealed a constitutive increase in the escape ability of D. pulicaria which may help them avoid attack by Bythotrephes. These data contribute to a growing body of research that demonstrates that ecological invasions can prompt adaptive responses, altering the nature of interactions between invasive predators and native prey species.