To understand the differences in diet and utilization of trophic resources between the upper and the lower reaches of rivers by the Japanese eel Anguilla japonica , we investigated the stomach contents of 207 specimens from both reaches of Tsuchikawa-gawa River, Kagoshima, Japan. The results indicate that there may be greater influence of terrestrial resources on the Japanese eel in the upper reach than that in the lower reach. In light of this, it is important to secure the connectivity between terrestrial and aquatic zones in the upper reaches of river which will aid in conservation efforts for the Japanese eel.

中文翻译：

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日本鹿儿岛土川河上游和下游地区的日本鳗鲡（Anguilla japonica）的饮食对比

为了解日本鳗鲡在河流上下游在饮食和营养资源利用方面的差异，我们调查了日本鹿儿岛土川河两岸207个标本的胃内容物。结果表明，陆地资源对上游鳗鲡的影响可能大于下游。有鉴于此，确保河流上游陆地和水域之间的连通性非常重要，这将有助于日本鳗鱼的保护工作。