Department of Biology - Aquatic Ecology, Lund University, Lund, Sweden.
International Centre for Ecohydraulics Research, Faculty of Engineering and Physical Sciences, Boldrewood Innovation Campus, University of Southampton, Southampton SO16 7QF, UK.
J Fish Biol. 2021 May;98(5):1234-1241. doi: 10.1111/jfb.14652. Epub 2021 Jan 18.
This study examines the impact of boldness on foraging competition of the highly invasive round goby Neogobius melanostomus Pallas 1815. Individual risk tolerance, or boldness, was measured as the time to resume movement after a simulated predation strike. Fish that resumed movement faster were categorized as "bold," fish that took more time to resume movement were categorized as "shy" and those that fell in between these two categories were determined to have "intermediate" boldness. Competitive impacts of boldness in N. melanostomus were determined in a laboratory foraging experiment in which interspecific (juvenile Atlantic cod Gadus morhua Linnaeus 1758) and intraspecific (intermediate N. melanostomus) individuals were exposed to either bold or shy N. melanostomus competitors. G. morhua consumed fewer prey when competing with bold N. melanostomus than when competing with shy N. melanostomus, whereas intermediately bold N. melanostomus foraging was not affected by competitor boldness. Bold and shy N. melanostomus consumed similar amounts of prey, and the number of interactions between paired fish did not vary depending on the personality of N. melanostomus individuals. Therefore, intraspecific foraging competition was not found to be personality dependent. This study provides evidence that individual differences in boldness can mediate competitive interactions in N. melanostomus; nonetheless, results also show that competition is also governed by other mechanisms that require further study.
本研究考察了大胆对高度入侵的圆鳍鱼 Neogobius melanostomus Pallas 1815 觅食竞争的影响。个体风险容忍度，或大胆程度，是通过模拟捕食攻击后恢复运动的时间来衡量的。恢复运动更快的鱼类被归类为“大胆”，恢复运动较慢的鱼类被归类为“害羞”，介于这两个类别之间的鱼类被确定为“中等”大胆。在实验室觅食实验中，确定了圆鳍鱼中大胆程度的竞争影响，在该实验中，种间（幼年大西洋鳕鱼 Gadus morhua Linnaeus 1758）和种内（中等圆鳍鱼）个体暴露于大胆或害羞的圆鳍鱼竞争者中。当与大胆的圆鳍鱼竞争时，大西洋鳕鱼消耗的猎物较少，而与害羞的圆鳍鱼竞争时则不然，而中等大胆的圆鳍鱼觅食则不受竞争者大胆程度的影响。大胆和害羞的圆鳍鱼消耗的猎物数量相似，并且配对鱼之间的相互作用次数不取决于圆鳍鱼个体的个性。因此，没有发现种内觅食竞争取决于个性。本研究提供的证据表明，大胆程度的个体差异可以调节圆鳍鱼中的竞争相互作用；尽管如此，结果还表明，竞争也受到其他需要进一步研究的机制的控制。
