The introduction of non-native species is recognized as a major threat to biodiversity, particularly in freshwater ecosystems. Pikeperch Sander lucioperca, is a recent invader to Portugal, primarily providing commercial and angling interest. The aim of this work was to study the diet of this top predator across Portuguese basins and to evaluate its potential impact on recipient ecosystems. In total, 256 pikeperch stomachs from seven basins were examined, of which 88 (n = 34%) were empty. Pikeperch diet was dominated by R. rutilus, M. salmoides and Diptera in northern populations, while A. alburnus, P. clarkii and Atyidae were important prey in more humid highlands. Variation in diet was most strongly linked to latitude and ontogeny, with both size classes showing signs of cannibalism. The population niche breadth remained low and was accompanied by higher individual diet specialization, particularly in northern populations. Pikeperch dietary patterns denoted an opportunistic ability to use locally abundant prey in each ecosystem, and was size dependent, with larger individuals becoming more piscivores, causing a higher impact in the lotic systems. This first perspective about the pikeperch diet presents a very broad view of the feeding traits of this non-native predator across Portugal, being very important to deepen our knowledge about the impact of these introduced piscivores.

中文翻译：

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葡萄牙盆地中入侵性顶级捕食者 Sander lucioperca (Linnaeus, 1758) 饮食模式的变化

非本地物种的引入被认为是对生物多样性的主要威胁，特别是在淡水生态系统中。Pikeperch Sander lucioperca是葡萄牙最近的入侵者，主要提供商业和钓鱼兴趣。这项工作的目的是研究葡萄牙盆地中这种顶级捕食者的饮食，并评估其对接收者生态系统的潜在影响。总共检查了来自七个盆地的 256 个鲈鱼胃，其中 88 个 ( n = 34%) 是空的。梭鲈的饮食是由主导河鲤，M.大口黑鲈和双翅目北方人群，而A.翘嘴鲌，克氏原螯和 Atyidae 是更潮湿的高地的重要猎物。饮食的变化与纬度和个体发育密切相关，两个大小等级都显示出自相残杀的迹象。人口生态位宽度仍然很低，并且伴随着更高的个体饮食专业化，特别是在北方人群中。梭鲈饮食模式表示在每个生态系统中利用当地丰富猎物的机会主义能力，并且取决于体型，体型较大的个体变得更加食鱼，从而对激流系统产生更大的影响。关于梭鲈饮食的第一个观点对葡萄牙这种非本地捕食者的摄食性状提出了非常广泛的看法，这对于加深我们对这些引入的食鱼动物的影响的了解非常重要。