Thambithurai Davide, Hollins Jack, Van Leeuwen Travis, Rácz Anita, Lindström Jan, Parsons Kevin, Killen Shaun S
Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Glasgow UK.
Cape Eleuthera Institute Eleuthera The Bahamas.
Ecol Evol. 2018 Jun 11;8(13):6505-6514. doi: 10.1002/ece3.4107. eCollection 2018 Jul.
Group living is widespread among animals and has a range of positive effects on individual foraging and predator avoidance. For fishes, capture by humans constitutes a major source of mortality, and the ecological effects of group living could carry-over to harvest scenarios if fish are more likely to interact with fishing gears when in social groups. Furthermore, individual metabolic rate can affect both foraging requirements and social behaviors, and could, therefore, have an additional influence on which fish are most vulnerable to capture by fishing. Here, we studied whether social environment (i.e., social group size) and metabolic rate exert independent or interactive effects on the vulnerability of wild zebrafish () to capture by a baited passive trap gear. Using video analysis, we observed the tendency for individual fish to enter a deployed trap when in different shoal sizes. Fish in larger groups were more vulnerable to capture than fish tested individually or at smaller group sizes. Specifically, focal fish in larger groups entered traps sooner, spent more total time within the trap, and were more likely to re-enter the trap after an escape. Contrary to expectations, there was evidence that fish with a higher SMR took longer to enter traps, possibly due to a reduced tendency to follow groupmates or attraction to conspecifics already within the trap. Overall, however, social influences appeared to largely overwhelm any link between vulnerability and metabolic rate. The results suggest that group behavior, which in a natural predation setting is beneficial for avoiding predators, could be maladaptive under a trap harvest scenario and be an important mediator of which traits are under harvest associated selection.
群居在动物中很普遍，对个体觅食和躲避捕食者有一系列积极影响。对于鱼类来说，被人类捕获是主要的死亡来源，如果鱼类在群居时更有可能与渔具相互作用，那么群居的生态影响可能会延续到捕捞场景中。此外，个体代谢率会影响觅食需求和社会行为，因此，可能会对哪些鱼类最容易被捕获产生额外影响。在这里，我们研究了社会环境（即社会群体大小）和代谢率对野生斑马鱼被诱饵被动陷阱渔具捕获的脆弱性是否具有独立或交互作用。通过视频分析，我们观察了不同鱼群大小下个体鱼进入已部署陷阱的倾向。较大群体中的鱼比较单独测试或较小群体大小的鱼更容易被捕获。具体来说，较大群体中的焦点鱼更快进入陷阱，在陷阱内停留的总时间更长，并且在逃脱后更有可能重新进入陷阱。与预期相反，有证据表明标准代谢率较高的鱼进入陷阱的时间更长，这可能是由于跟随同伴的倾向降低或对陷阱内同种鱼的吸引力降低。然而，总体而言，社会影响似乎在很大程度上掩盖了脆弱性与代谢率之间的任何联系。结果表明，在自然捕食环境中有利于躲避捕食者的群体行为，在陷阱捕捞场景下可能是适应不良的，并且是与捕捞相关选择下哪些特征受到影响的重要调节因素。
