Variation in behaviour of native prey mediates the impact of an invasive species on plankton communities

PeerJ. 2024 Dec 12:12:e18608. doi: 10.7717/peerj.18608. eCollection 2024.

Abstract

Trait variation in predator populations can influence the outcome of predator-prey dynamics, with consequences for trophic dynamics and ecosystem functioning. However, the influence of prey trait variation on the impacts of predators is not well understood, especially for introduced predators where variation in prey can shape invasion outcomes. In this study, we investigated if intra-specific differences in vertical position of Daphnia influenced the impacts of the invasive zooplankton predator, Bythotrephes cederströmii, on plankton communities. Our results show that vertical position of Daphnia influenced Bythotrephes predation on smaller cladoceran species and impacts on primary production. Larger reductions in small cladoceran density and greater algal biomass were observed in mesocosms with less spatial overlap between Daphnia and Bythotrephes. These results suggest that differences in vertical position of Daphnia can alter the type and magnitude of Bythotrephes impacts in invaded systems.

Keywords: Anti-predator response; Daphnia catawba; Daphnia mendotae; Intraspecific trait variation; Trophic cascade; Vertical distribution; Zooplankton.

MeSH terms

  • Animals
  • Biomass
  • Daphnia* / physiology
  • Ecosystem
  • Food Chain
  • Introduced Species*
  • Plankton* / physiology
  • Population Dynamics
  • Predatory Behavior* / physiology
  • Zooplankton / physiology

Grants and funding

Funding for this project was provided by the Canadian Aquatic Invasive Species Network II (CAISN II), an Ontario Graduate Scholarship, and a graduate research award from the Muskoka Summit for the Environment. Support was also provided through the Queen’s University Summer Work Experience Program (SWEP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.