Calanus hyperboreus is a large-bodied, biomass dominant species that performs a crucial ecosystem energy transfer by converting the spring phytoplankton bloom into lipid reserves that fuel the higher trophic levels of the Gulf of St. Lawrence (GSL) pelagic ecosystem, including the critically endangered North Atlantic right whale (Eubalena glacialis). Given that the GSL, the southernmost core habitat of C. hyperboreus, is undergoing rapid warming, developing a population model allows us to synthesize existing knowledge of the species, and to examine the species response to environmental conditions. To simulate the multi-year life cycle in the northwest GSL, model equations are implemented for ingestion, assimilation, respiration, egg production, stage development, mortality, and vertical migration behaviors including dormancy entry and exit. The 1-D particle-based model predicts the evolution of individual stage, structural mass, lipid, age, sex, abundance, and egg production, as well as the seasonal evolution of the population structure in the northwest GSL. Individual lipid-based thresholds inform the timing of ontogenetic vertical migration. Life cycle targets defined from a literature review are used to guide model parameterization and assess its performance. The simulated population structure, phenology, and size at stage are generally consistent with observations. Under 10 years of repeat year forcing, the model simulates a quasi-stable overwintering population composed of late stages CIV, CV and CVI. Observations suggest that stage CIV is the first overwintering stage in the GSL, and point to the occurrence of iteroparous females. Using the model, the relative success of diverse dormancy and reproductive phenotypes are explored. Second reproduction females reproduce earlier in winter than first reproduction females, with implications for the ability of the new generation to match the spring bloom and accumulate sufficient lipid to overwinter as stage CIV. Without iteroparity, the time window of reproduction contracts and the population is reduced, underscoring the role of a flexible multi-year life cycle in population success.

中文翻译：

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对北极桡足类动物的完整生命周期进行建模揭示了并发生命周期策略之间的复杂权衡


Calanus hyperboreus 是一种体型庞大、生物量占优势的物种，通过将春季浮游植物大量繁殖转化为脂质储备来执行重要的生态系统能量转移，从而为圣劳伦斯湾 （GSL） 中上层生态系统的较高营养水平提供燃料，包括极度濒危的北大西洋露脊鲸 （Eubalena glacialis）。鉴于 Gsl 是 C. hyperboreus 最南端的核心栖息地，正在经历快速变暖，开发种群模型使我们能够综合该物种的现有知识，并检查物种对环境条件的反应。为了模拟西北 GSL 的多年生命周期，对摄入、同化、呼吸、产蛋、阶段发育、死亡率和垂直迁移行为（包括休眠进入和退出）实施了模型方程。基于一维粒子的模型预测了 GSL 西北部个体阶段、结构质量、脂质、年龄、性别、丰度和产蛋量的演变，以及种群结构的季节性演变。基于脂质的个体阈值告知个体发育垂直迁移的时间。从文献综述中定义的生命周期目标用于指导模型参数化并评估其性能。模拟的种群结构、物候和阶段规模与观测结果基本一致。在 10 年的重复年强迫下，该模型模拟了由晚期 CIV、CV 和 CVI 组成的准稳定的越冬种群。观察表明，CIV 阶段是 GSL 中的第一个越冬阶段，并指向斜生雌性的出现。使用该模型，探索了不同休眠和生殖表型的相对成功。 第二次繁殖的雌性比第一次繁殖的雌性在冬季繁殖得更早，这对新一代与春季开花相匹配并积累足够的脂质作为 CIV 阶段越冬的能力产生影响。没有迭代性，繁殖的时间窗口就会收缩，种群数量就会减少，这凸显了灵活的多年生命周期在种群成功中的作用。