Agüera Antonio, Ahn In-Young, Guillaumot Charlène, Danis Bruno
Laboratoire de Biologie Marine CP160/15. Université Libre de Bruxelles, Brussels, Belgium.
Korea Polar Research Institute (KOPRI), Yeonsu-gu, Incheon, Republic of Korea.
PLoS One. 2017 Aug 29;12(8):e0183848. doi: 10.1371/journal.pone.0183848. eCollection 2017.
Antarctic marine organisms are adapted to an extreme environment, characterized by a very low but stable temperature and a strong seasonality in food availability arousing from variations in day length. Ocean organisms are particularly vulnerable to global climate change with some regions being impacted by temperature increase and changes in primary production. Climate change also affects the biotic components of marine ecosystems and has an impact on the distribution and seasonal physiology of Antarctic marine organisms. Knowledge on the impact of climate change in key species is highly important because their performance affects ecosystem functioning. To predict the effects of climate change on marine ecosystems, a holistic understanding of the life history and physiology of Antarctic key species is urgently needed. DEB (Dynamic Energy Budget) theory captures the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model is a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. In this study, we estimate the DEB model parameters for the bivalve Laternula elliptica using literature-extracted and field data. The DEB model we present here aims at better understanding the biology of L. elliptica and its levels of adaptation to its habitat with a special focus on food seasonality. The model parameters describe a metabolism specifically adapted to low temperatures, with a low maintenance cost and a high capacity to uptake and mobilise energy, providing this organism with a level of energetic performance matching that of related species from temperate regions. It was also found that L. elliptica has a large energy reserve that allows enduring long periods of starvation. Additionally, we applied DEB parameters to time-series data on biological traits (organism condition, gonad growth) to describe the effect of a varying environment in food and temperature on the organism condition and energy use. The DEB model developed here for L. elliptica allowed us to improve benchmark knowledge on the ecophysiology of this key species, providing new insights in the role of food availability and temperature on its life cycle and reproduction strategy.
南极海洋生物适应了极端环境，其特点是温度极低但稳定，且由于日照长度变化导致食物供应具有强烈的季节性。海洋生物特别容易受到全球气候变化的影响，一些地区受到温度上升和初级生产力变化的冲击。气候变化还会影响海洋生态系统的生物组成部分，并对南极海洋生物的分布和季节性生理产生影响。了解气候变化对关键物种的影响非常重要，因为它们的表现会影响生态系统功能。为了预测气候变化对海洋生态系统的影响，迫切需要全面了解南极关键物种的生活史和生理学。动态能量平衡（DEB）理论将生物体在其整个生命周期中的代谢过程描述为温度和食物供应的函数。DEB模型是一种工具，可用于模拟生物一生的摄食、生长、繁殖及其对生物和非生物条件变化的反应。在本研究中，我们利用文献提取的数据和实地数据估算双壳贝类椭圆侧带蛤的DEB模型参数。我们在此提出的DEB模型旨在更好地了解椭圆侧带蛤的生物学特性及其对栖息地的适应水平，特别关注食物季节性。模型参数描述了一种特别适应低温的新陈代谢，维持成本低，摄取和调动能量的能力高，使这种生物的能量表现水平与温带地区的相关物种相当。研究还发现，椭圆侧带蛤有大量能量储备，使其能够忍受长时间的饥饿。此外，我们将DEB参数应用于生物特征（生物体状况、性腺生长）的时间序列数据，以描述食物和温度变化的环境对生物体状况和能量利用的影响。这里为椭圆侧带蛤开发的DEB模型使我们能够完善关于这一关键物种生态生理学的基准知识，为食物供应和温度对其生命周期和繁殖策略的作用提供新的见解。
