Abstract A 12-year time series (2005–2016) was examined to explore relationships between European anchovy density, growth, reproduction and habitat dynamics in an upwelling system. Specifically, data used for a daily egg production method were combined with oceanographic data, prey availability, as well as acoustic surveys of the anchovy stock in the Strait of Sicily, in the Central Mediterranean Sea. Variables typically used for evaluating habitat dynamics (i.e. water temperature, chlorophyll-a, zooplankton concentration, kinetic energy, mixed layer depth and upwelling index) indicated strong upwelling events during the summer, when anchovy spawns. A linear ‘principal component’ combination of environmental traits, associated with summer upwelling, was identified by step-wise regression as a driver for growth (length at the end of the first year; L1), reproductive investment (gonad-somatic index; GSI), as well as egg production (daily specific fecundity; DSF). These relationships are consistent with direct energy flow from the environment to both somatic growth and reproductive output, indicating an income breeding strategy by anchovy (i.e. surplus energy acquired during the summer breeding season is used directly for reproductive growth). Step-wise regression also identified three additional relationships: (1) a density-dependent mechanism reducing growth (L1) and fecundity (DSF) at higher fish densities; (2) higher fish condition (Kn) positively affecting growth (L1); (3) higher prey availability (mesozooplankton concentration) positively affecting GSI. This time series and approach are promising for exploring the abiotic and biotic mechanisms setting year class strength in advance of recruitment to the fishery.

中文翻译：

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西西里海峡欧洲凤尾鱼 (Engraulis encrasicolus) 的产卵生态：将上升流系统中浮游动物猎物、鱼类密度、生长和繁殖的变化联系起来

摘要 研究了 12 年时间序列（2005-2016），以探索上升流系统中欧洲鳀鱼密度、生长、繁殖和栖息地动态之间的关系。具体来说，将用于每日产蛋方法的数据与海洋学数据、猎物可用性以及对地中海中部西西里海峡鳀鱼种群的声学调查相结合。通常用于评估栖息地动态的变量（即水温、叶绿素-a、浮游动物浓度、动能、混合层深度和上升流指数）表明在鳀鱼产卵的夏季有强烈的上升流事件。与夏季上升流相关的环境特征的线性“主要成分”组合被逐步回归确定为增长的驱动因素（第一年年底的长度；L1)、生殖投资（性腺体细胞指数；GSI）以及产蛋量（每日特定繁殖力；DSF）。这些关系与从环境到体细胞生长和生殖输出的直接能量流一致，表明凤尾鱼的收入繁殖策略（即在夏季繁殖季节获得的多余能量直接用于繁殖生长）。逐步回归还确定了三个额外的关系：(1) 密度依赖机制在较高的鱼密度下降低生长 (L1) 和繁殖力 (DSF)；(2) 较高的鱼况 (Kn) 对生长有积极影响 (L1)；(3) 较高的猎物可用性（中浮游生物浓度）对 GSI 产生积极影响。