Davis Brittany E, Miller Nathan A, Flynn Erin E, Todgham Anne E
Department of Animal Sciences, University of California Davis, Davis, CA 95616, USA Department of Wildlife, Fish and Conservation Biology, University of California Davis, Davis, CA 95616, USA.
Department of Animal Sciences, University of California Davis, Davis, CA 95616, USA Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920, USA.
J Exp Biol. 2016 Apr 15;219(Pt 8):1203-13. doi: 10.1242/jeb.133173. Epub 2016 Mar 4.
To date, numerous studies have shown negative impacts of CO2-acidified seawater (i.e. ocean acidification, OA) on marine organisms, including calcifying invertebrates and fishes; however, limited research has been conducted on the physiological effects of OA on polar fishes and even less on the impact of OA on early developmental stages of polar fishes. We evaluated aspects of aerobic metabolism and cardiorespiratory physiology of juvenile emerald rockcod, ITALIC! Trematomus bernacchii, an abundant fish in the Ross Sea, Antarctica, to elevated partial pressure of carbon dioxide ( ITALIC! PCO2 ) [420 (ambient), 650 (moderate) and 1050 (high) μatm ITALIC! PCO2 ] over a 1 month period. We examined cardiorespiratory physiology, including heart rate, stroke volume, cardiac output and ventilation rate, whole organism metabolism via oxygen consumption rate and sub-organismal aerobic capacity by citrate synthase enzyme activity. Juvenile fish showed an increase in ventilation rate under high ITALIC! PCO2 compared with ambient ITALIC! PCO2 , whereas cardiac performance, oxygen consumption and citrate synthase activity were not significantly affected by elevated ITALIC! PCO2 Acclimation time had a significant effect on ventilation rate, stroke volume, cardiac output and citrate synthase activity, such that all metrics increased over the 4 week exposure period. These results suggest that juvenile emerald rockcod are robust to near-future increases in OA and may have the capacity to adjust for future increases in ITALIC! PCO2 by increasing acid-base compensation through increased ventilation.
迄今为止，大量研究表明，二氧化碳酸化海水（即海洋酸化，OA）对海洋生物有负面影响，包括钙化无脊椎动物和鱼类；然而，关于OA对极地鱼类生理影响的研究有限，而关于OA对极地鱼类早期发育阶段影响的研究更少。我们评估了南极罗斯海一种数量丰富的鱼类——幼年翡翠岩鳕（学名：Trematomus bernacchii）在1个月时间内，暴露于升高的二氧化碳分压（PCO₂）[420（环境水平）、650（中度）和1050（高度）微大气压PCO₂]下的有氧代谢和心肺生理学方面的情况。我们检查了心肺生理学指标，包括心率、每搏输出量、心输出量和通气率，通过耗氧率评估整体生物代谢，并通过柠檬酸合酶活性评估亚生物体有氧能力。与环境PCO₂相比，幼年鱼在高PCO₂条件下通气率增加，而升高的PCO₂对心脏功能、耗氧量和柠檬酸合酶活性没有显著影响。驯化时间对通气率、每搏输出量、心输出量和柠檬酸合酶活性有显著影响，以至于在4周的暴露期内所有指标都有所增加。这些结果表明，幼年翡翠岩鳕对近期OA的增加具有耐受性，并且可能有能力通过增加通气来增强酸碱补偿，以适应未来PCO₂的增加。
