Seawater carbonate chemistry and life history traits and feeding of the littoral mysid Praunus flexuosus

Mysids, an important food web component in the littoral zone of coastal waters, have been neglected so far in ocean acidification research. Juveniles of the littoral mysid Praunus flexuosus were exposed in the laboratory to four pCO2 levels (530, 930, 1200, and 1600 µatm) for 5 weeks. In addition, juveniles were provided with two different food levels during the experiment. High pCO2 did not affect survival, but delayed moulting. Juvenile growth decreased and inter-moult period between the last moulting events increased with increasing pCO2 at low but not at high food supply, suggesting that high food availability is needed to prevent these negative effects of elevated pCO2. However, small individual juveniles showed lower feeding rates at high pCO2 compared to the control after prolonged exposure, suggesting decreased activity likely due to impaired metabolism. The subtle negative effects of elevated pCO2 on life history traits observed in this study suggest that P. flexuosus probably has to adapt to counteract adverse effects of predicted high pCO2, especially when food is limiting.

糠虾作为沿岸水域潮间带食物网的重要组成部分，迄今为止在海洋酸化研究中仍被忽视。研究人员在实验室中将潮间带糠虾Praunus flexuosus幼体暴露于四种二氧化碳分压（pCO₂）水平（530、930、1200和1600微大气压）下，持续5周。此外，实验期间为幼体提供了两种不同的食物浓度。高二氧化碳分压未影响幼体存活率，但延缓了其蜕皮过程。在低食物供给条件下，随着二氧化碳分压升高，幼体生长速率下降，末次蜕皮事件间的蜕壳间期延长；而高食物供给条件下则无此现象，这表明需充足食物才能抵消高二氧化碳分压带来的负面效应。然而，长期暴露后，体型较小的幼体在高二氧化碳分压下的摄食率低于对照组，这可能是由于代谢受损导致其活动能力下降所致。本研究观察到的高二氧化碳分压对生活史特征的细微负面影响表明，弯曲秀体糠虾（P. flexuosus）可能需通过适应来抵消未来高二氧化碳分压的不利影响，尤其是在食物受限的情况下。