Effects of COsub2/sub-driven ocean acidification on early life stages of marine medaka (iOryzias melastigma/i)

摘要

The potential effects of high CO₂ and associated ocean acidification(OA) in marine fishes and other non-calcified organisms are less wellunderstood. In this study, we investigated the responses of early life stages(ELS) of marine medaka (Oryzias melastigma) exposed to a series ofexperimental manipulation of CO₂ levels. Results showed thatCO₂-driven seawater acidification (pH 7.6 and pH 7.2) had nodetectable effect on hatching time, hatching rate, or heart rate of embryos.However, the deformity rate of larvae in the pH 7.2 treatment wassignificantly higher than that in the control treatment. There is nosignificant difference between the left and right otolith areas in eachtreatment. However, the average otolith area of larvae in the pH 7.6treatment was significantly smaller than that in the control. Suchalterations in the developmental abnormalities and otolith size of marinemedaka larvae due to elevated-CO₂ levels suggests that this species willbe increasingly challenged by future OA. Further studies of the impacts of OAon marine fish to assess whether or not the environmental influence in onegeneration can affect the later life history and the phenotype of subsequentgenerations are needed.