Habitat modification by invasive crayfish can facilitate its growth through enhanced food accessibility

BMC Ecology

Research Article

Chisato Nishikawa¹  Tadashi Miyashita¹  Shota Nishijima² 

[1] Laboratory of Biodiversity Science, School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, 113-8657, Tokyo, Japan;Laboratory of Biodiversity Science, School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, 113-8657, Tokyo, Japan;National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, 236-8648, Kanazawa, Yokohama, Japan;

关键词: Interaction modification;    Invasive engineer;    Macrophyte refuge;    Positive density dependence;    Red swamp crayfish;    Submerged plants;   

DOI  :  10.1186/s12898-017-0147-7

 received in 2017-09-19, accepted in 2017-11-16,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundInvasive ecosystem engineers can facilitate their invasions by modifying the physical environment to improve their own performance, but this positive feedback process has rarely been tested empirically except in sessile organisms. The invasive crayfish Procambarus clarkii is an ecosystem engineer that destroys aquatic macrophytes, which provide a physical refuge for animal prey, and this destruction is likely to enhance vulnerability to predators. Using two series of mesocosm experiments, we tested the hypothesis that the invasive crayfish increases its feeding efficiency on animal prey by reducing submerged macrophytes, thus increasing its individual growth rate in a positive density-dependent manner.ResultsIn the first experiment, increasing crayfish density reduced both macrophytes and animal prey (dragonfly and chironomid larvae) and, importantly, increased the growth rate of individual crayfish, in accordance with our expectation. In the second experiment, we used artificial macrophytes to clarify whether the physical architecture of macrophytes itself protects animal prey and limits crayfish growth rate. Increasing the artificial macrophyte quantity not only increased the survival of animal prey, but also retarded the crayfish growth rate.ConclusionsWe conclude that macrophytes strengthen bottom-up control of crayfish, but this effect can be relaxed by increasing the density of crayfish via reduction in macrophytes. This positive feedback process may explain the crayfish outbreaks and regime shifts occasionally observed in invaded freshwater ecosystems.

【 授权许可】

CC BY   
© The Author(s) 2017