Comparative feeding ecology of invasive Ponto-Caspian gobies
Comparative feeding ecology of invasive Ponto-Caspian gobies
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DOI：
10.1007/s10750-012-1349-9
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发表时间：
2013-02-01
期刊：
影响因子：
2.6
通讯作者：
Geist, Juergen
中科院分区：
文献类型：
--
作者：
Brandner, Joerg;Auerswald, Karl;Geist, Juergen
据怀疑，庞托-里海格比亚鱼的入侵可能会导致淡水生态系统的状况发生变化。本研究利用稳定同位素分析(三角洲C-13和三角洲N-15)、肠道内容物分析和消化道形态计量学分析，比较了多瑙河上游黑口新眼鱼和凯氏黄鱼的营养生态位分化。这两个物种都被鉴定为捕食性杂食性动物，具有高度的食物重叠和通用的摄食策略。两足类(尤其是入侵的Dikerogammarus spp)对食物重要性指数的贡献为2/3。黑口藻的N-15特征表明个体发育的食性变化，并且显著超过克氏原甲藻1.5欧氏度，表明生态位分离的营养水平的一半。Kessleri的未盘绕的肠道比黑口黑口夜蛾短，这表明它们的生态位较窄，对动物食物的适应程度较低。在生长期，两种动物的营养生态位都在扩大，kessleri在行会内捕食和自相残杀的行为增加，而黑口藻的软体动物数量增加。Kessleri具有更高的专化度和更稳定的季节摄食模式，而黑口黑口鱼则根据自然猎物的可获得性来调整其食物。在多瑙河上游观察到的这两个物种的摄食模式与它们原生范围内的摄食模式有很大的不同，这突显了它们巨大的可塑性。这两种虎鱼主要摄食其他非本地物种(与92%的肠道内容物相似)，而且似乎受益于之前对被捕食物种的入侵，如簇毛虎鱼。虎鱼及其猎物的入侵成功反映了欧洲大型淡水生态系统的根本生态变化。
Invasions of Ponto-Caspian gobiid fishes are suspected to cause regime shifts in freshwater ecosystems. This study compared the trophic niche differentiations of Neogobius melanostomus and Ponticola kessleri in the upper Danube River using stable isotope analyses (delta C-13 and delta N-15), gut content analyses and morphometric analyses of the digestive tract. Both species were identified as predacious omnivores with high dietary overlap and a generalistic feeding strategy. Amphipods (especially invasive Dikerogammarus spp.) contributed 2/3 to the index of food importance. delta N-15-signatures of N. melanostomus revealed an ontogenetic diet shift and significantly exceeded those in P. kessleri by similar to 1.5aEuro degrees, indicating a niche separation of half a trophic level. P. kessleri had shorter uncoiled intestinal tracts than N. melanostomus, indicating a narrower niche and adaptation to animal food. Trophic niches in both species expanded during the growth period with increasing intraguild predation and cannibalism in P. kessleri and increasing molluscivory in N. melanostomus. P. kessleri showed a higher degree of specialization and more stable feeding patterns across seasons, whereas N. melanostomus adapted its diet according to the natural prey availability. The feeding patterns of both species observed in the upper Danube River strongly differ from those in their native ranges, underlining their great plasticity. Both goby species consumed mainly other non-native species (similar to 92% of gut contents) and seemed to benefit from previous invasions of prey species like Dikerogammarus villosus. The invasive success of gobies and their prey mirror fundamental ecological changes in large European freshwater ecosystems.