Ucrit data larvae sea bass

Udrict data measured in the European sea bass larvae from 17 to 56 days-post-hatch (dph) reared at a combination of two temperature (15°C and 20°C) and three PCO2 levels (ambient, ~1000 µatm and ~1700µatm)

Future ocean warming may prove beneficial for the northern population of European seabass, but ocean acidification will not

The world's oceans are acidifying and warming as a result of increasing atmospheric CO2 concentrations. The thermal tolerance of fish greatly depends on the cardiovascular ability to supply the tissues with oxygen. The highly oxygen-dependent heart mitochondria thus might play a key role in shaping an organism's tolerance to temperature. The present study aimed to investigate the effects of acute and chronic warming on the respiratory capacity of European sea bass (Dicentrarchus labrax L.) heart mitochondria. We hypothesized that acute warming would impair mitochondrial respiratory capacity, but be compensated for by life-time conditioning. Increasing PCO2 may additionally cause shifts in metabolic pathways by inhibiting several enzymes of the cellular energy metabolism. Among other shifts in metabolic pathways, acute warming of heart mitochondria of cold life-conditioned fish increased leak respiration rate, suggesting a lower aerobic capacity to synthesize ATP with acute warming. However, thermal conditioning increased mitochondrial functionality, e.g. higher respiratory control ratios in heart mitochondria of warm life-conditioned compared with cold life-conditioned fish. Exposure to high PCO2 synergistically amplified the effects of acute and long-term warming, but did not result in changes by itself. This high ability to maintain mitochondrial function under ocean acidification can be explained by the fact that seabass are generally able to acclimate to a variety of environmental conditions. Improved mitochondrial energy metabolism after warm conditioning could be due to the origin of this species in the warm waters of the Mediterranean. Our results also indicate that seabass are not yet fully adapted to the colder temperatures in their northern distribution range and might benefit from warmer temperatures in these latitudes

Experimental conditions, respiration rates of permeabilized heart fibres and biometrical data of European seabass Dicentrarchus labrax

The world's oceans are acidifying and warming as a result of increasing atmospheric CO2 concentrations. The thermal tolerance of fish greatly depends on the cardiovascular ability to supply the tissues with oxygen. The highly oxygen-dependent heart mitochondria thus might play a key role in shaping an organism's tolerance to temperature. The present study aimed to investigate the effects of acute and chronic warming on the respiratory capacity of European sea bass (Dicentrarchus labrax L.) heart mitochondria. Broodstock fish were caught in the Gulf of Morbihan, France. Larvae were raised at the aquaculture facility Aquastream (Ploemeur-Lorient, France) and obtained at 2 dph (20 January 2016). European sea bass were reared in the laboratory in six ocean acidification and warming (OAW) conditions: two temperatures (warm and cold life condition) and three PCO2 conditions (control, Δ500 and Δ1000). Conditions were chosen to follow the predictions of the IPCC for the next 130 years: ΔT = 5°C and ΔPCO2 = 500 and 1000 µatm, following RCP 6.0 and RCP 8.5 respectively. The fish were reared under these conditions from 3 dph (days post hatch) until mitochondrial respiration measurements at 3700 to 4100 dd (degree days, 183–199 dph and 234–249 dph in warm and cold life conditioned fish, respectively). During the experimental period, fish of all three PCO2 conditions of the respective temperature were used for mitochondrial respiration measurements on permeabilized heart fibres. Fish were not fed for 2 days prior to the experiments. Two batches of eight fish each were processed per day. Juveniles were randomly caught from their tanks and anesthetized with MS-222. Mass, fork length and body length were directly determined with a precision balance (Mettler, Columbus, OH, USA) and a calliper, to the nearest 0.01 g and 0.01 mm, respectively. Afterwards, fish were killed by a cut through the neck, and the heart was completely dissected from the fish, followed by excavation and permeabilization of the ventricle. Tissue from a whole ventricle was used for respiration measurements in each respiration chamber of the oxygraphs and respiration rates were normalized to ventricle mass. During the permeabilization step, the livers and the carcasses of the fish were weighed to calculate the hepatosomatic index (HSI) and condition factor (K). Mitochondrial respiration of the permeabilized heart fibres was measured using four Oroboros Oxygraph-2K respirometers with DatLab 6 software (Oroboros Instruments, Innsbruck, Austria). Permeabilized fibers have the advantage of resembling the living state as closely as possible, while still allowing control of the supply of substrates and inhibitors to the mitochondria (Saks et al., 1998; Pesta and Gnaiger, 2012). Measurements were conducted at 15 and 20°C for all treatments to determine the effect of acute temperature changes on mitochondrial metabolism in vitro. A standard substrate–uncoupler–inhibitor titration protocol was employed to measure the respiration rates of the different complexes. Residual respiration after antimycin A addition was used to correct all mitochondrial respiration rates

Data from: Combined effects of ocean acidification and temperature on larval and juvenile growth, development and swimming performance of European sea bass (Dicentrarchus labrax)

Ocean acidification and ocean warming (OAW) are simultaneously occurring and could pose ecological challenges to marine life, particularly early life stages of fish that, although they are internal calcifiers, have poorly developed acid-base regulation. This study assessed the effect of projected OAW on key fitness traits (growth, development and swimming ability) in European sea bass (Dicentrarchus labrax) larvae and juveniles. Starting at 2 days post-hatch (dph), larvae were exposed to one of three levels of PCO₂ (650, 1150, 1700 µatm; pH 8.0, 7.8, 7.6) at either a cold (15°C) or warm (20°C) temperature. Growth rate, development stage and critical swimming speed (Ucrit) were repeatedly measured as sea bass grew from 0.6 to ~10.0 (cold) or ~14.0 (warm) cm body length. Exposure to different levels of PCO₂ had no significant effect on growth, development or Ucrit of larvae and juveniles. At the warmer temperature, larvae displayed faster growth and deeper bodies. Notochord flexion occurred at 0.8 and 1.2 cm and metamorphosis was completed at an age of ~45 and ~60 days post-hatch for sea bass in the warm and cold treatments, respectively. Swimming performance increased rapidly with larval development but better swimmers were observed in the cold treatment, reflecting a potential trade-off between fast grow and swimming ability. A comparison of the results of this and other studies on marine fish indicates that the effects of OAW on the growth, development and swimming ability of early life stages are species-specific and that generalizing the impacts of climate-driven warming or ocean acidification is not warranted

Oxygen consumption of F0 and F1 larval and juvenile European seabass Dicentrarchus labrax in resonse to ocean acidification and warming

Ongoing climate change is leading to warmer and more acidic oceans. The future distribution of fish within the oceans depends on their capacity to adapt to these new environments. Only few studies have examined the effects of ocean acidification (OA) and warming (OW) on the metabolism of long-lived fish over successive generations. We therefore aimed to investigate the effect of OA on larval and juvenile growth and metabolism on two successive generations of European sea bass (Dicentrarchus labrax L.) as well as the effect of OAW on larval and juvenile growth and metabolism of the second generation. European sea bass is a large economically important fish species with a long generation time. F0 larvae were produced at the aquaculture facility Aquastream (Ploemeur-Lorient, France) and obtained at 2 days post-hatch (dph). From 2 dph F0 larvae were reared in the laboratory in two PCO2 conditions (ambient and Δ1000). Larval rearing was performed in a temperature controlled room and water temperatures were fixed to 19°C in F0. In juveniles and adults, water temperatures of F0 sea bass were adjusted to ambient temperature in the Bay of Brest during summer (up to 19°C), but were kept constant at 15 and 12°C for juveniles and adults, respectively, when ambient temperature decreased below these values. F1 embryos were obtained by artificial reproduction of F0 broodstock fish. Fertilized eggs were incubated at 15°C and at the same PCO2 conditions as respective F0. Division of F1 larvae from egg rearing tanks into experimental tanks took place at 2 dph. F1 larvae were reared in four OAW conditions: two temperatures (cold and warm life condition, C and W) and two PCO2 conditions (ambient and Δ1000). Larval rearing was performed in a temperature controlled room and water temperatures were fixed to 15 and 20°C for C and W larvae, respectively. In juveniles, water temperatures of F1 sea bass were adjusted to ambient temperature in the Bay of Brest during summer (up to 19°C), but were kept constant at 15°C when ambient temperature decreased below these values. F1-W was always 5°C warmer than the F1-C treatment. OAW conditions for F0 and F1 rearing were chosen to follow the predictions of the IPCC for the next 130 years: ΔT = 5°C and ΔPCO2 = 1000 µatm, following RCP 8.5. We analysed larval and juvenile growth in F0 and F1. Larval routine metabolic rates (RMR, in F1), juvenile standard metabolic rates (SMR, in F0 and F1) and juvenile critical oxygen concentrations (PO2crit, in F0 and F1) were obtained on individuals via intermittent flow-respirometry. Measurements were conducted at the rearing conditions of the respective larva or juvenile. Fish were fasted for 3h and 48-72h for larvae and juveniles, respectively. After the respirometry trial, larvae were photographed to measure there body length and frozen until measurement of dry mass. Juveniles body length and wet mass was directly determined with calipers and a balance

Growth rates of F0 and F1 larval and juvenile European seabass Dicentrarchus labrax in resonse to ocean acidification and warming

Ongoing climate change is leading to warmer and more acidic oceans. The future distribution of fish within the oceans depends on their capacity to adapt to these new environments. Only few studies have examined the effects of ocean acidification (OA) and warming (OW) on the metabolism of long-lived fish over successive generations. We therefore aimed to investigate the effect of OA on larval and juvenile growth and metabolism on two successive generations of European sea bass (Dicentrarchus labrax L.) as well as the effect of OAW on larval and juvenile growth and metabolism of the second generation. European sea bass is a large economically important fish species with a long generation time. F0 larvae were produced at the aquaculture facility Aquastream (Ploemeur-Lorient, France) and obtained at 2 days post-hatch (dph). From 2 dph F0 larvae were reared in the laboratory in two PCO2 conditions (ambient and Δ1000). Larval rearing was performed in a temperature controlled room and water temperatures were fixed to 19°C in F0. In juveniles and adults, water temperatures of F0 sea bass were adjusted to ambient temperature in the Bay of Brest during summer (up to 19°C), but were kept constant at 15 and 12°C for juveniles and adults, respectively, when ambient temperature decreased below these values. F1 embryos were obtained by artificial reproduction of F0 broodstock fish. Fertilized eggs were incubated at 15°C and at the same PCO2 conditions as respective F0. Division of F1 larvae from egg rearing tanks into experimental tanks took place at 2 dph. F1 larvae were reared in four OAW conditions: two temperatures (cold and warm life condition, C and W) and two PCO2 conditions (ambient and Δ1000). Larval rearing was performed in a temperature controlled room and water temperatures were fixed to 15 and 20°C for C and W larvae, respectively. In juveniles, water temperatures of F1 sea bass were adjusted to ambient temperature in the Bay of Brest during summer (up to 19°C), but were kept constant at 15°C when ambient temperature decreased below these values. F1-W was always 5°C warmer than the F1-C treatment. OAW conditions for F0 and F1 rearing were chosen to follow the predictions of the IPCC for the next 130 years: ΔT = 5°C and ΔPCO2 = 1000 µatm, following RCP 8.5. We analysed larval and juvenile growth in F0 and F1. Larval routine metabolic rates (RMR, in F1), juvenile standard metabolic rates (SMR, in F0 and F1) and juvenile critical oxygen concentrations (PO2crit, in F0 and F1) were obtained on individuals via intermittent flow-respirometry. Measurements were conducted at the rearing conditions of the respective larva or juvenile. Fish were fasted for 3h and 48-72h for larvae and juveniles, respectively. After the respirometry trial, larvae were photographed to measure there body length and frozen until measurement of dry mass. Juveniles body length and wet mass was directly determined with calipers and a balance

Respiration and growth rates of F0 and F1 larval and juvenile European seabass Dicentrarchus labrax in response to ocean acidification and warming

Ongoing climate change is leading to warmer and more acidic oceans. The future distribution of fish within the oceans depends on their capacity to adapt to these new environments. Only few studies have examined the effects of ocean acidification (OA) and warming (OW) on the metabolism of long-lived fish over successive generations. We therefore aimed to investigate the effect of OA on larval and juvenile growth and metabolism on two successive generations of European sea bass (Dicentrarchus labrax L.) as well as the effect of OAW on larval and juvenile growth and metabolism of the second generation. European sea bass is a large economically important fish species with a long generation time. F0 larvae were produced at the aquaculture facility Aquastream (Ploemeur-Lorient, France) and obtained at 2 days post-hatch (dph). From 2 dph F0 larvae were reared in the laboratory in two PCO2 conditions (ambient and Δ1000). Larval rearing was performed in a temperature controlled room and water temperatures were fixed to 19°C in F0. In juveniles and adults, water temperatures of F0 sea bass were adjusted to ambient temperature in the Bay of Brest during summer (up to 19°C), but were kept constant at 15 and 12°C for juveniles and adults, respectively, when ambient temperature decreased below these values. F1 embryos were obtained by artificial reproduction of F0 broodstock fish. Fertilized eggs were incubated at 15°C and at the same PCO2 conditions as respective F0. Division of F1 larvae from egg rearing tanks into experimental tanks took place at 2 dph. F1 larvae were reared in four OAW conditions: two temperatures (cold and warm life condition, C and W) and two PCO2 conditions (ambient and Δ1000). Larval rearing was performed in a temperature controlled room and water temperatures were fixed to 15 and 20°C for C and W larvae, respectively. In juveniles, water temperatures of F1 sea bass were adjusted to ambient temperature in the Bay of Brest during summer (up to 19°C), but were kept constant at 15°C when ambient temperature decreased below these values. F1-W was always 5°C warmer than the F1-C treatment. OAW conditions for F0 and F1 rearing were chosen to follow the predictions of the IPCC for the next 130 years: ΔT = 5°C and ΔPCO2 = 1000 µatm, following RCP 8.5. We analysed larval and juvenile growth in F0 and F1. Larval routine metabolic rates (RMR, in F1), juvenile standard metabolic rates (SMR, in F0 and F1) and juvenile critical oxygen concentrations (PO2crit, in F0 and F1) were obtained on individuals via intermittent flow-respirometry. Measurements were conducted at the rearing conditions of the respective larva or juvenile. Fish were fasted for 3h and 48-72h for larvae and juveniles, respectively. After the respirometry trial, larvae were photographed to measure there body length and frozen until measurement of dry mass. Juveniles body length and wet mass was directly determined with calipers and a balance

Food availability modulates the combined effects of ocean acidification and warming on fish growth

International audienceWhen organisms are unable to feed ad libitum they may be more susceptible to negative effects of environmental stressors such as ocean acidification and warming (OAW). We reared sea bass (Dicentrarchus labrax) at 15 or 20 °C and at ambient or high PCO2 (650 versus 1750 µatm PCO2; pH = 8.1 or 7.6) at ad libitum feeding and observed no discernible effect of PCO2 on the size-at-age of juveniles after 277 (20 °C) and 367 (15 °C) days. Feeding trials were then conducted including a restricted ration (25% ad libitum). At 15 °C, growth rate increased with ration but was unaffected by PCO2. At 20 °C, acidification and warming acted antagonistically and low feeding level enhanced PCO2 effects. Differences in growth were not merely a consequence of lower food intake but also linked to changes in digestive efficiency. The specific activity of digestive enzymes (amylase, trypsin, phosphatase alkaline and aminopeptidase N) at 20 °C was lower at the higher PCO2 level. Our study highlights the importance of incorporating restricted feeding into experimental designs examining OAW and suggests that ad libitum feeding used in the majority of the studies to date may not have been suitable to detect impacts of ecological significance