Faria, A. M.Lopes, A. F.Silva, C. S. E.Novais, S. C.Lemos, M. F. L.Gonçalves, E. J.2018-05-102020-06-012018-061879-02910141-1136http://hdl.handle.net/10400.8/3238This work had the support of Fundação para a Ciência e Tecnologia through the project ACIDLARVAE (PTDC/MAR-EST/4627/2012) and project PROTEOME (PTDC/AAG-MAA/1302/2014), co-financed by COMPETE (POCI-01-0145-FEDER-016773), grants to Ana M. Faria (SFRH/BPD/68673/2010), Cátia Silva (SFRH/BD/118195/2016), and Sara C. Novais (SFRH/BPD/94500/2013), a L'oreal award for Women in Science (2015) to Ana M. Faria, and the strategic project UID/MAR/ 04292/2013. The authors also wish to acknowledge the Integrated Programme of SR&TD “Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate” (reference Centro-01- 0145-FEDER-000018), co-funded by Centro (2020) program, Portugal 2020, European Union, through the European Regional Development Fund.Fishes are currently facing novel types of anthropogenic stressors that have never experienced in their evolutionary history, such as ocean acidification. Under these stressful conditions, energetically costly processes, such as reproduction, may be sacrificed for increased chances of survival. This trade-off does not only affect the organism itself but may result in reduced offspring fitness. In the present study, the effects of exposure to high pCO2 levels were tested on the reproductive performance of a temperate species, the two-spotted goby, Gobiusculus flavescens. Breeding pairs were kept under control (∼600 μatm, pH∼ 8.05) and high pCO2 levels (∼2300 μatm, pH∼ 7.60) conditions for a 4-month period. Additionally, oxidative stress and energy metabolism-related biomarkers were measured. Results suggest that reproductive activity is stimulated under high pCO2 levels. Parental pairs in the simulated ocean acidification conditions exhibited increased reproductive output, with 50% more clutches and 44% more eggs per clutch than pairs under control conditions. However, there was an apparent trade-off between offspring number and size, as larvae of parental pairs under high pCO2 levels hatched significantly smaller, suggesting differences in parental provisioning, which could be related to the fact that these females produce more eggs. Moreover, results support the hypothesis of different energy allocation strategies used by females under high pCO2 conditions. These changes might, ultimately, affect individual fitness and population replenishment.engBiomarkerEnergy metabolismFishGobiusculus flavescensOcean acidificationReproductive successjournal article10.1016/j.marenvres.2018.02.027