Finely tuned response of native prey to an invasive predator in a freshwater system

Abstract

Abstract. Lack of shared evolutionary history reduces the expectation that native prey will detect and respond to invasive predators. Four mechanisms may explain the adaptive response that is nevertheless seen in various systems: prey may perceive the invasive predator through cue similarity with preexisting predators, cues of conspecifics eaten by the invasive predator, a learned response based on experience with the invasive predator (e.g., cue association), and cues from the invasive predator that are specific to it. We performed laboratory experiments in which zooplankton (Daphnia mendotae) responded adaptively to the zooplanktivore Bythotrephes longimanus (migrating downward), showed no response to taxonomically similar predatory cladocerans, and responded adaptively to more taxonomically distant native fish (migrating downward) and native shrimp (migrating upward). Conspecific cues associated with Bythotrephes predation actually reduced the response of D. mendotae to Bythotrephes. Combined with previous experiments that rule out learning, our experiments rule out the first three mechanisms above, demonstrating that D. mendotae respond to cues specific to and produced directly by Bythotrephes. This finely tuned response may be retained from an ancestral species that coevolved with Bythotrephes in its native range, or may have rapidly evolved due to strong selection by the invasive predator.

Rapid evolution of constitutive and inducible defenses against an invasive predator

“…These results strongly suggest that the morphological response to P. clarkii in the long coexistence 1 population is adaptive, indicating that this population has evolved plastic morphological defenses against the invasive crayfish. While our study reports the fastest evolution of antipredator responses documented for an amphibian (;30 years, 10-15 P. perezi generations), there are several studies reporting rapid evolution in response to selection by invasive predators (Schlaepfer et al 2005, Freeman and Byers 2006, Strauss et al 2006, Bourdeau et al 2013, including in an amphibian (Kiesecker and Blaustein 1997). Taken together, our results agree with the idea that invasive species can be a strong selective force generating local adaptation and rapid evolution (Strauss et al 2006, Sih et al 2010.…”

A plague of waterfleas (Bythotrephes): impacts on microcrustacean community structure, seasonal biomass, and secondary production in a large inland-lake complex

“…However, the escape response of D. mendotae to Bythotrephes is also fairly effective (PichlovaPtacnikova and Vanderploeg 2011). It is intriguing that D. mendotae in the Laurentian Great Lakes contain D. galeata genes (Kerfoot and Weider 2004), which might account for some of the superior evasive traits (Bourdeau et al 2013). Although not a smallbodied cladoceran, Daphnia pulicaria was severely reduced to one tenth of its former abundance.…”

Rapid evolution mitigates the ecological consequences of an invasive species (Bythotrephes longimanus) in lakes in Wisconsin

“…However, it is important to note that Daphnia respond to the presence of Bythotrephes by migrating to deeper depths [43,44]. This is because the risk of predation declines with depth.…”