Understanding the Metabolic Capacity of Antarctic Fishes to Acclimate to Future Ocean Conditions
Understanding the Metabolic Capacity of Antarctic Fishes to Acclimate to Future Ocean Conditions
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DOI：
10.1093/icb/icaa121
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发表时间：
2020-12-01
影响因子：
2.6
通讯作者：
Mandic，Milica
中科院分区：
文献类型：
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作者：
Todgham，Anne E.;Mandic，Milica
南极鱼类在稳定的极端低温下进化了数百万年。它们适应在寒冷的环境中茁壮成长，其特殊的表型可能使它们特别容易受到气候变化导致的未来海洋变暖和酸化的影响。从一个稳定的时期到一个环境变化的时期，物种的持续生存将取决于保持能量平衡，或维持增加的能量需求，而不损害重要的生物功能，如生长和繁殖。适应环境的代谢能力，通过常规代谢率（RMR）的生理补偿恢复代谢平衡，可能会决定哪些物种将更好地科普环境条件的变化。重点关注南极鱼类的优势类群Notothenioidei，特别是四个研究充分的物种，Trematomus bernacchii，Pagothenia borchgrevinki，Notothenia rossii，和N.coriiceps，我们讨论了代谢驯化潜力变暖和CO2酸化使用一个综合和比较的框架。在变暖过程中RMR的生理补偿和实现补偿所需的适应时间的持续时间方面存在物种特异性差异;对于某些物种，RMR在暴露后3.5周内完全恢复，如P。borchgrevinki，而其他物种，如N.在暴露9周后，Coriiceps的RMR仍显著升高。在所有情况下，增加暴露于增加的PCO 2，进一步损害了物种将RMR恢复到暴露前水平的能力。以RMR升高为标志的代谢失衡时期，强调了能量干扰和能量成本升高，这将能量从与健康相关的功能（如生长）转移。在T. bernacchiiandN.长时间的RMR升高影响条件因子和/或生长速率。低生长率会影响发育，并最终影响繁殖的时间，严重损害物种的生存潜力和Notothenioid谱系的生物多样性。因此，为了避免代谢失衡的长期后果，在短时间内实现RMR完全补偿的能力可能是物种在不断变化的环境中持续生存的能力的重要决定因素。仍然需要做很多工作，以发展我们的南极鱼类的生物能量学在面对环境变化的理解，嵌套在生态和比较框架的机械重点的有针对性的方法，将更好地帮助我们预测全球气候变化对物种的持久性在极地地区的影响。
Antarctic fishes have evolved under stable, extreme cold temperatures for millions of years. Adapted to thrive in the cold environment, their specialized phenotypes will likely render them particularly susceptible to future ocean warming and acidification as a result of climate change. Moving from a period of stability to one of environmental change, species persistence will depend on maintaining energetic equilibrium, or sustaining the increased energy demand without compromising important biological functions such as growth and reproduction. Metabolic capacity to acclimate, marked by a return to metabolic equilibrium through physiological compensation of routine metabolic rate (RMR), will likely determine which species will be better poised to cope with shifts in environmental conditions. Focusing on the suborder Notothenioidei, a dominant group of Antarctic fishes, and in particular four well-studied species,Trematomus bernacchii,Pagothenia borchgrevinki,Notothenia rossii, andN.coriiceps, we discuss metabolic acclimation potential to warming and CO2-acidification using an integrative and comparative framework. There are species-specific differences in the physiological compensation of RMR during warming and the duration of acclimation time required to achieve compensation; for some species, RMR fully recovered within 3.5 weeks of exposure, such asP. borchgrevinki, while for other species, such asN. coriiceps, RMR remained significantly elevated past 9 weeks of exposure. In all instances, added exposure to increasedPCO2, further compromised the ability of species to return RMR to pre-exposure levels. The period of metabolic imbalance, marked by elevated RMR, was underlined by energetic disturbance and elevated energetic costs, which shifted energy away from fitness-related functions, such as growth. InT. bernacchiiandN. coriiceps, long duration of elevated RMR impacted condition factor and/or growth rate. Low growth rate can affect development and ultimately the timing of reproduction, severely compromising the species’ survival potential and the biodiversity of the notothenioid lineage. Therefore, the ability to achieve full compensation of RMR, and in a short-time frame, in order to avoid long term consequences of metabolic imbalance, will likely be an important determinant in a species’ capacity to persist in a changing environment. Much work is still required to develop our understanding of the bioenergetics of Antarctic fishes in the face of environmental change, and a targeted approach of nesting a mechanistic focus in an ecological and comparative framework will better aid our predictions on the effect of global climate change on species persistence in the polar regions.