metabolism

JEB publishes paper on metabolic effects of high CO2 in silverside embryos! [New publication]

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19 November 2020. We are happy to announce that the Journal of Experimental Biology just published the latest paper on CO2 effects in the early life stages of Atlantic silversides! For her PhD research at Stony Brook University, Teresa meticulously measured oxygen consumption in developing silverside embryos and newly hatched larvae exposed to contrasting oxygen and CO2 conditions throughout multiple experiments in 2017 and 2018. Her work shows that the metabolism of embryos but not larvae is sensitive to elevated CO2 conditions, leading to higher metabolic rates at normoxic levels, but reduced metabolic rates under low oxygen conditions, compared to controls. These basic empirical data confirm the emerging picture that CO2 effects in marine fish manifest largely if at all during early ontogeny, i.e., during the embryo stages. Well done, Teresa, and congratulations to your first lead-author paper!
Schwemmer-etal
Conceptual diagram of the relationship between PO2 and RMR of M. menidia embryos in ambient and elevated PCO2. Hypothesized shifts in the relationship between embryonic RMR and PO2 are shown for elevated (orange) versus ambient (blue) PCO2. Our results (measured at the PO2 levels marked by black dots) suggest that PCO2 can influence both the critical oxygen partial pressure (Pcrit, gray lines) and the oxygen-independent RMR. At higher PO2 levels, RMR increases with PCO2, potentially owing to increased metabolic demand. As PO2 decreases, embryonic RMR reaches Pcrit and becomes oxygen dependent at a higher PO2 level in acidified than in ambient PCO2 conditions. Low intracellular red blood cell pH caused by high PCO2 can be expected to reduce hemoglobin–O2 affinity (Bohr effect) and make embryonic RMR less hypoxia resistant, which could manifest as an increase in Pcrit for embryos in elevated PCO2.