Cattano Carlo, Giomi Folco, Milazzo Marco
Department of Earth and Marine Sciences (DiSTeM) and CoNISMa , University of Palermo , Via Archirafi 28 I-90123, Palermo , Italy.
Conserv Physiol. 2016 Feb 26;4(1):cov073. doi: 10.1093/conphys/cov073. eCollection 2016.
Volcanic CO2 seeps provide opportunities to investigate the effects of ocean acidification on organisms in the wild. To understand the influence of increasing CO2 concentrations on the metabolic rate (oxygen consumption) and the development of ocellated wrasse early life stages, we ran two field experiments, collecting embryos from nesting sites with different partial pressures of CO2 [pCO2; ambient (∼400 µatm) and high (800-1000 µatm)] and reciprocally transplanting embryos from ambient- to high-CO2 sites for 30 h. Ocellated wrasse offspring brooded in different CO2 conditions had similar responses, but after transplanting portions of nests to the high-CO2 site, embryos from parents that spawned in ambient conditions had higher metabolic rates. Although metabolic phenotypic plasticity may show a positive response to high CO2, it often comes at a cost, in this case as a smaller size at hatching. This can have adverse effects because smaller larvae often exhibit a lower survival in the wild. However, the adverse effects of increased CO2 on metabolism and development did not occur when embryos from the high-CO2 nesting site were exposed to ambient conditions, suggesting that offspring from the high-CO2 nesting site could be resilient to a wider range of pCO2 values than those belonging to the site with present-day pCO2 levels. Our study identifies a crucial need to increase the number of studies dealing with these processes under global change trajectories and to expand these to naturally high-CO2 environments, in order to assess further the adaptive plasticity mechanism that encompasses non-genetic inheritance (epigenetics) through parental exposure and other downstream consequences, such as survival of larvae.
火山二氧化碳渗漏为研究海洋酸化对野生生物的影响提供了机会。为了了解二氧化碳浓度升高对眼斑海猪鱼早期生命阶段代谢率（氧气消耗）和发育的影响，我们进行了两项野外实验，从具有不同二氧化碳分压 [pCO₂；环境水平（约400 μatm）和高浓度（800 - 1000 μatm）] 的筑巢地点收集胚胎，并将胚胎从环境二氧化碳环境移植到高二氧化碳环境中30小时。在不同二氧化碳条件下孵化的眼斑海猪鱼后代有相似的反应，但将部分巢穴移植到高二氧化碳环境后，在环境条件下产卵的亲体的胚胎具有更高的代谢率。尽管代谢表型可塑性可能对高二氧化碳表现出积极反应，但这往往是有代价的，在这种情况下代价是孵化时体型较小。这可能会产生不利影响，因为较小的幼体在野外的存活率通常较低。然而，当来自高二氧化碳筑巢地点的胚胎暴露于环境条件时，二氧化碳增加对代谢和发育的不利影响并未出现，这表明来自高二氧化碳筑巢地点的后代可能比现今处于环境二氧化碳水平地点的后代对更广泛的pCO₂值具有更强的适应能力。我们的研究明确指出，迫切需要增加在全球变化轨迹下研究这些过程的数量，并将这些研究扩展到天然高二氧化碳环境中，以便进一步评估适应性可塑性机制，该机制包括通过亲体暴露的非遗传遗传（表观遗传学）以及其他下游后果，如幼体的存活率。
