Barrow Joshua S, Yen Jian D L, Koehn John D, Zampatti Brenton, Fanson Ben, Thiem Jason D, Tonkin Zeb, Koster Wayne M, Butler Gavin L, Strawbridge Arron, Brooks Steven G, Woods Ryan, Morrongiello John R
Biosciences 4, The University of Melbourne, Parkville, VIC, Australia.
Department of Energy, Environment and Climate Action, Arthur Rylah Institute for Environmental Research, 123 Brown Street, Heidelberg, VIC, Australia.
Mov Ecol. 2025 Mar 17;13(1):18. doi: 10.1186/s40462-025-00541-w.
Variation in somatic growth plays a critical role in determining an individual's body size and the expression of its life history. Understanding the environmental drivers of growth variation in mobile organisms such as fishes can be challenging because an individual's growth expression integrates processes operating at different spatial and temporal scales. Traditionally, otolith (ear stone) based growth analyses have focussed on temporal environmental variation by assuming an individual spends its whole life at its capture location. This approach ignores the movement potential of individuals and thus the role of spatio-temporal variation in conditions experienced. Here, we develop a modelling framework that incorporates individual movement information reconstructed via the analysis of chemical tracers in otoliths. We assess whether consideration of movement histories is important to estimating growth of a mobile freshwater fish, golden perch (Macquaria ambigua) at three spatial resolutions: basin-scale, reach-scale (movement-exclusive), and reach-scale (movement-inclusive). The predictive capacity of annual growth models slightly improved from the basin to the reach spatial scales (inclusive or exclusive of movement histories). Contrary to expectations, incorporating individual movement information, did not improve our ability to describe growth patterns. Golden perch growth was linked to the magnitude of and variation in spring, summer, and previous-year (antecedent) discharge, and spring temperature. The direction and magnitude of these effects was, however, dependent on life stage. Adults benefitted strongly from any increase in discharge or temperature, whereas juveniles benefitted only from increased summer discharge and grew slower in years characterised by wetter and warmer springs. We suggest that, for highly mobile fish like golden perch and in the absence of fine, 'within reach' scale biological data, coarser 'reach-scale' environmental variation may adequately describe individual growth trajectories.
体细胞生长的变化在决定个体体型及其生活史表达方面起着关键作用。对于鱼类等移动生物而言，了解生长变化的环境驱动因素颇具挑战性，因为个体的生长表现整合了在不同时空尺度上运作的过程。传统上，基于耳石（耳内结石）的生长分析通过假设个体在捕获地点度过一生来聚焦于时间环境变化。这种方法忽略了个体的移动潜力，进而忽略了所经历条件的时空变化的作用。在此，我们开发了一个建模框架，该框架纳入了通过耳石中化学示踪剂分析重建的个体移动信息。我们评估在三个空间分辨率下考虑移动历史对于估计一种移动性淡水鱼——金鲈（Macquaria ambigua）的生长是否重要：流域尺度、河段尺度（排除移动）和河段尺度（包含移动）。从流域到河段空间尺度（包含或排除移动历史），年度生长模型的预测能力略有提高。与预期相反，纳入个体移动信息并未提高我们描述生长模式的能力。金鲈的生长与春季、夏季和前一年（前期）流量的大小及变化以及春季温度相关。然而，这些影响的方向和大小取决于生活阶段。成年金鲈从流量或温度的任何增加中都能大幅受益，而幼鱼仅从夏季流量增加中受益，并且在春季更湿润、更温暖的年份生长较慢。我们认为，对于像金鲈这样高度移动的鱼类，并且在缺乏精细的“河段内”尺度生物学数据的情况下，较粗略的“河段尺度”环境变化可能足以描述个体生长轨迹。
