Pavel Franta, Radek Gebauer, Lukáš Veselý, Natalia Z. Szydłowska, Bořek Drozd
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引用次数: 0
Abstract
Abundance and per-capita foraging efficiency are essential factors for predicting and quantifying an invasive predator impact on prey, i.e., the impact potential (IP). However, population structure is not included in the calculation, and IP accuracy might be improved by incorporating predator body size. The population structure of the round goby Neogobius melanostomus , a highly invasive predator, was surveyed in the Elbe River. We determined the functional response (FR, per capita foraging) of the three most abundant size classes of N. melanostomus on the water louse Asellus aquaticus . We then calculated the IP for each size class and for the entire population with (the actual impact potential – IP A ) and without (the impact potential for limit size rage – IP LSR ) population body size structure (based on FR of the medium size class). All three size classes of the predator showed type II FR with respect to A. aquaticus . The estimated FR parameters, attack rate and handling time, as well as the maximum feeding rate, were size dependent. Despite the lowest per capita foraging efficiency, small individuals displayed the highest IP among the tested size classes because of their high abundance. Conversely, medium and large individuals, although showing highest per capita foraging efficiency, displayed lower IP. Hence, IP A showed more precise IP calculations compared to IP LSR . Overestimation of the potential impact as a consequence of omitting predator population size structure was negligible at the investigated locality. The IP of the N. melanostomus population five years post-invasion can be accurately calculated based on the FR of medium-sized fish.
丰度和人均觅食效率是预测和量化入侵捕食者对猎物影响的重要因素,即影响潜力(IP)。然而,种群结构不包括在计算中,IP的准确性可以通过纳入捕食者的体型来提高。对易北河地区高入侵性捕食者圆虾虎鱼(Neogobius melanostomus)的种群结构进行了调查。测定了3个最丰富的大小纲黑口螨对水虱的功能响应(FR,人均觅食)。然后,我们计算了每个大小类别以及具有(实际影响潜力- IP A)和不具有(限制大小范围的影响潜力- IP LSR)人口体型结构(基于中等大小类别的FR)的整个人口的IP。3个大小类别的捕食者均表现为II型FR。估算的FR参数、攻击速率和处理时间以及最大进料速率与大小有关。尽管小个体的人均觅食效率最低,但由于它们的丰度高,在测试的大小类别中表现出最高的IP。相反,中型和大型个体虽然具有最高的人均觅食效率,但其IP较低。因此,与IP LSR相比,IP A显示出更精确的IP计算。在被调查地区,由于忽略捕食者种群规模结构而导致的潜在影响的高估是可以忽略不计的。根据中型鱼的FR,可以准确地计算出黑口黑鲈种群入侵5年后的IP。
期刊介绍:
Aquatic Invasions is an open access, peer-reviewed international journal focusing on academic research of biological invasions in both inland and coastal water ecosystems from around the world.
It was established in 2006 as initiative of the International Society of Limnology (SIL) Working Group on Aquatic Invasive Species (WGAIS) with start-up funding from the European Commission Sixth Framework Programme for Research and Technological Development Integrated Project ALARM.
Aquatic Invasions is an official journal of International Association for Open Knowledge on Invasive Alien Species (INVASIVESNET).
Aquatic Invasions provides a forum for professionals involved in research of aquatic non-native species, including a focus on the following:
• Patterns of non-native species dispersal, including range extensions with global change
• Trends in new introductions and establishment of non-native species
• Population dynamics of non-native species
• Ecological and evolutionary impacts of non-native species
• Behaviour of invasive and associated native species in invaded areas
• Prediction of new invasions
• Advances in non-native species identification and taxonomy