Growth, metabolism, anatomy, behaviour, invertebrate drift

Adaptive trade-offs are fundamental mechanisms underlying phenotypic diversity, but the presence of generalizable patterns in multivariate adaptation and their mapping onto environmental gradients remain unclear.
To understand how life-history affects multivariate trait associations, we examined relationships among growth, metabolism, anatomy and behaviour in rainbow trout juveniles from piscivore vs. insectivore ecotypes along an experimental gradient of food availability. We hypothesized that i) selection for larger size in piscivorous adults would select for higher juvenile growth at the cost of lower active metabolism; ii) elevated growth of piscivores would be supported by a greater productivity of their natal stream and more proactive foraging behaviours; and iii) general patterns of multivariate trait associations would match the predictions of the Pace-Of-Life Syndrome.
Relative to insectivores, piscivorous fry showed a pattern of higher growth (+63%), maximum food intake...

适应性权衡（adaptive trade-offs）是表型多样性（phenotypic diversity）背后的核心机制，但目前学界尚未明确多变量适应（multivariate adaptation）中是否存在普适性模式，亦未厘清这些模式与环境梯度（environmental gradients）的对应关系。
为阐明生活史（life-history）如何影响多变量性状关联，本研究围绕食物可获得性的实验梯度，对食鱼生态型与食虫生态型虹鳟（rainbow trout）幼体的生长、代谢、解剖结构与行为间的关联展开了分析。我们提出三项假说：① 食鱼型成体对更大体型的选择压力，会以降低主动代谢（active metabolism）为代价，驱动幼体获得更高的生长速率；② 食鱼型个体更高的生长水平，可依托其出生溪流更高的生产力与更积极的觅食行为（foraging behaviour）得以支撑；③ 多变量性状关联的普适性模式，将与生活节奏综合征（Pace-Of-Life Syndrome）的理论预测相符。
相较于食虫型个体，食鱼型虹鳟鱼苗呈现出更高的生长模式（增幅达63%）、最大食物摄入量……