Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12589, Berlin, Germany.
Faculty of Life Sciences, Humboldt University, Invalidenstrasse 42, 10115, Berlin, Germany.
Sci Rep. 2021 Feb 9;11(1):3440. doi: 10.1038/s41598-021-81568-y.
Intraspecific diet specialization, usually driven by resource availability, competition and predation, is common in natural populations. However, the role of parasites on diet specialization of their hosts has rarely been studied. Eye flukes can impair vision ability of their hosts and have been associated with alterations of fish feeding behavior. Here it was assessed whether European perch (Perca fluviatilis) alter their diet composition as a consequence of infection with eye flukes. Young-of-the-year (YOY) perch from temperate Lake Müggelsee (Berlin, Germany) were sampled in two years, eye flukes counted and fish diet was evaluated using both stomach content and stable isotope analyses. Perch diet was dominated by zooplankton and benthic macroinvertebrates. Both methods indicated that with increasing eye fluke infection intensity fish had a more selective diet, feeding mainly on the benthic macroinvertebrate Dikerogammarus villosus, while less intensively infected fish appeared to be generalist feeders showing no preference for any particular prey type. Our results show that infection with eye flukes can indirectly affect interaction of the host with lower trophic levels by altering the diet composition and highlight the underestimated role of parasites in food web studies.
种内的饮食特化通常由资源可用性、竞争和捕食驱动，在自然种群中很常见。然而，寄生虫对宿主饮食特化的作用很少被研究。眼吸虫会损害宿主的视力能力，并与鱼类摄食行为的改变有关。本研究评估了欧洲鲈鱼（Perca fluviatilis）是否会因感染眼吸虫而改变其饮食组成。从德国柏林的穆格尔湖（Müggelsee）采集了两年的幼鱼（YOY），计数眼吸虫并使用胃内容物和稳定同位素分析来评估鱼类的饮食。鲈鱼的饮食主要由浮游动物和底栖大型无脊椎动物组成。两种方法都表明，随着眼吸虫感染强度的增加，鱼类的饮食更具选择性，主要以底栖大型无脊椎动物 Dikerogammarus villosus 为食，而感染较轻的鱼类似乎是杂食性的，对任何特定的猎物类型都没有偏好。我们的结果表明，感染眼吸虫可以通过改变饮食组成间接影响宿主与较低营养级别的相互作用，并强调了寄生虫在食物网研究中被低估的作用。
