Hollins J P W, Thambithurai D, Van Leeuwen T E, Allan B, Koeck B, Bailey D, Killen S S
Institute of Biodiversity, Animal Health and Comparative Medicine, Graham Kerr Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
Fisheries and Oceans Canada, Salmonid Section, 80 East White Hills Road, PO Box 5667, St. John's, Newfoundland A1C 5X1, Canada.
Conserv Physiol. 2019 Jul 26;7(1):coz043. doi: 10.1093/conphys/coz043. eCollection 2019.
Impacts of fisheries-induced evolution may extend beyond life history traits to more cryptic aspects of biology, such as behaviour and physiology. Understanding roles of physiological traits in determining individual susceptibility to capture in fishing gears and how these mechanisms change across contexts is essential to evaluate the capacity of commercial fisheries to elicit phenotypic change in exploited populations. Previous work has shown that metabolic traits related to anaerobic swimming may determine individual susceptibility to capture in trawls, with fish exhibiting higher anaerobic performance more likely to evade capture. However, high densities of fish aggregated ahead of a trawl net may exacerbate the role of social interactions in determining an individual fish's behaviour and likelihood of capture, yet the role of social environment in modulating relationships between individual physiological traits and vulnerability to capture in trawls remains unknown. By replicating the final moments of capture in a trawl using shoals of wild minnow (), we investigated the role of individual metabolic traits in determining susceptibility to capture among shoals of both familiar and unfamiliar conspecifics. We expected that increased shoal cohesion and conformity of behaviour in shoals of familiar fish would lessen the role of individual metabolic traits in determining susceptibility to capture. However, the opposite pattern was observed, with individual fish exhibiting high anaerobic capacity less vulnerable to capture in the trawl net, but only when tested alongside familiar conspecifics. This pattern is likely due to stronger cohesion within familiar shoals, where maintaining a minimal distance from conspecifics, and thus staying ahead of the net, becomes limited by individual anaerobic swim performance. In contrast, lower shoal cohesion and synchronicity of behaviours within unfamiliar shoals may exacerbate the role of stochastic processes in determining susceptibility to capture, disrupting relationships between individual metabolic traits and vulnerability to capture.
渔业诱导进化的影响可能不仅限于生活史特征，还会延伸到生物学中更隐秘的方面，如行为和生理。了解生理特征在决定个体对渔具捕获易感性方面的作用，以及这些机制如何随环境变化，对于评估商业渔业在被开发种群中引发表型变化的能力至关重要。先前的研究表明，与无氧游泳相关的代谢特征可能决定个体对拖网捕获的易感性，无氧性能较高的鱼类更有可能逃避捕获。然而，拖网前方聚集的高密度鱼群可能会加剧社会互动在决定个体鱼类行为和捕获可能性方面的作用，但社会环境在调节个体生理特征与拖网捕获易感性之间关系方面的作用仍不明确。通过使用野生米诺鱼群模拟拖网捕获的最后时刻，我们研究了个体代谢特征在决定熟悉和不熟悉的同种鱼群中捕获易感性方面的作用。我们预期，熟悉鱼类群体中群体凝聚力的增强和行为的一致性会降低个体代谢特征在决定捕获易感性方面的作用。然而，观察到的却是相反的模式，个体无氧能力高的鱼在拖网中被捕的可能性较小，但只有在与熟悉的同种鱼一起测试时才是如此。这种模式可能是由于熟悉的鱼群内部凝聚力更强，在这种情况下，与同种鱼保持最小距离并因此保持在网前，会受到个体无氧游泳能力的限制。相比之下，不熟悉的鱼群中较低的群体凝聚力和行为同步性可能会加剧随机过程在决定捕获易感性方面的作用，破坏个体代谢特征与捕获易感性之间的关系。
