Foraging behavior of yellow-phase Japanese eels between connected fresh- and brackish water habitats
Foraging behavior of yellow-phase Japanese eels between connected fresh- and brackish water habitats
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DOI：
10.1007/s10641-020-01002-6
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发表时间：
2020-07-14
影响因子：
1.4
通讯作者：
Yamashita, Yoh
中科院分区：
文献类型：
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作者：
Kutzer, Alisa;Lavergne, Edouard;Yamashita, Yoh
日本鳗（Anguilla japonica）在内陆水域的生长阶段利用沿海洋-淡水过渡带的广泛栖息地。本研究旨在通过碳（δ C-13）和氮（δ N-15）稳定同位素的分析，分析淡水和咸淡水连接生境中黄相日本鳗的觅食行为，并将觅食行为与生境利用联系起来。对在淡水和咸淡水中采集的鳗鱼胃内容物进行了分析，以确定食物来源。分析了松川村咸淡水泻湖和三条淡水支流中鳗鱼及其潜在食物来源的δ C-13和δ N-15值，并用于预测鳗鱼近期的觅食模式。鳗鱼捕食底栖河流群落和泻湖的泥滩群落。在淡淡水和半咸淡水生境中，虾蛄鱼是鳗鱼的重要食物来源，而日本大闸蟹（Eriocheir japonica）和滨蟹（Hemigrapsusspp.）分别是鳗鱼的主要猎物。在淡淡水和半咸淡水生境中，鳗鱼的潜在猎物δ C-13值存在显著差异，并利用δ C-13值对73条鳗鱼最近的三种觅食模式进行了分类：1)淡水觅食；2)咸淡水觅食；3)多生境觅食。数据表明，一些鳗鱼最近或经常在淡水和咸淡水栖息地之间移动，而另一些则对淡水或咸淡水表现出更高的保真度。不同觅食生境中猎物的同位素特征揭示了研究区黄鳝生境利用的可塑性。本研究展示了一种综合研究鳗鱼生境利用和觅食行为的方法。此外，该研究强调需要考虑淡水和河口栖息地以及它们之间的连通性，以进行鳗鱼管理和保护。
Japanese eels (Anguilla japonica) utilize a broad range of habitats along the marine-freshwater ecotone during their growth phase in inland waters. This study aimed to analyze the foraging behavior of yellow-phase Japanese eels in connected fresh- and brackish water habitats and to connect foraging behavior and habitat use through the analysis of carbon (delta C-13) and nitrogen (delta N-15) stable isotopes. Stomach contents of eels collected in fresh- and brackish waters were analyzed to identify food sources. Values of delta C-13 and delta N-15 were analyzed in eels and their potential food sources, and used to predict the recent foraging patterns of eels in the Matsukawa-ura, a brackish water lagoon, and in three freshwater tributaries. Eels preyed on the benthic river community and the mudflat community of the lagoon. Gobiid fishes were found to be an important food source for eels in fresh- and brackish water habitats, while Japanese mitten crabs (Eriocheir japonica) and shore crabs (Hemigrapsusspp.) were major prey in fresh- and brackish waters respectively.delta C-13 values of potential eel prey differed significantly between fresh- and brackish waters and were used to classify three recent patterns of foraging by the 73 eels included in this study: 1) freshwater foraging, 2) brackish water foraging, and 3) multiple-habitat foraging. The data suggested that some eels recently or frequently moved between fresh- and brackish water habitats while others demonstrated a higher fidelity to either fresh- or brackish waters. Isotopic characteristics of prey in the respective foraging habitats revealed the plasticity of habitat use of yellow eels in the study area. This study demonstrates an integrated approach to study habitat use and foraging behavior of eels. Furthermore, the study underlines the need to consider freshwater and estuarine habitats and the connectivity between them for eel management and conservation.