Cardiovascular oxygen transport and peripheral oxygen extraction capacity contribute to acute heat tolerance in European seabass.

This study evaluated whether different parameters describing cardiovascular function, energy metabolism, oxygen transport and oxidative stress were related to the critical thermal maximum (CT) of European seabass (Dicentrarchus labrax) and if there were differential changes in these parameters during and after heat shock in animals with different CT in order to characterize which physiological features make seabass vulnerable to heat waves. Seabass (n = 621) were tested for CT and the physiological parameters were measured in individuals with good or poor temperature tolerance before and after a heat shock (change in temperature from 15 °C to 28 °C in 1.5 h).

Warm, but not hypoxic acclimation, prolongs ventricular diastole and decreases the protein level of Na/Ca exchanger to enhance cardiac thermal tolerance in European sea bass.

One of the physiological mechanisms that can limit the fish's ability to face hypoxia or elevated temperature, is maximal cardiac performance. Yet, few studies have measured how cardiac electrical activity and associated calcium cycling proteins change with acclimation to those environmental stressors. To examine this, we acclimated European sea bass for 6 weeks to three experimental conditions: a seasonal average temperature in normoxia (16 °C; 100% air sat.

Effects of dispersant-treated oil upon behavioural and metabolic parameters of the anti-predator response in juvenile European sea bass (Dicentrarchus labrax).

Acute exposure to oil and oil dispersants can cause a wide range of physiological dysfunctions in marine fish species and evidences for consequences on behaviour are also increasing. In response to the presence of predators or to food availability, the modulation of locomotor activity and schools' behaviour enable fish to maximize their survival rates. However, the degree to which this regulatory process is affected by exposure to oil and/or dispersants is yet unknown.

Effects of ocean acidification over successive generations decrease resilience of larval European sea bass to ocean acidification and warming but juveniles could benefit from higher temperatures in the NE Atlantic.

European sea bass (Dicentrarchus labrax) is a large, economically important fish species with a long generation time whose long-term resilience to ocean acidification (OA) and warming (OW) is not clear. We incubated sea bass from Brittany (France) for two generations (>5 years in total) under ambient and predicted OA conditions (PCO2: 650 and 1700 µatm) crossed with ambient and predicted OW conditions in F1 (temperature: 15-18°C and 20-23°C) to investigate the effects of climate change on larval and juvenile growth and metabolic rate. We found that in F1, OA as a single stressor at ambient temperature did not affect larval or juvenile growth and OW increased developmental time and growth rate, but OAW decreased larval size at metamorphosis.

Effects of dispersant treated oil upon exploratory behaviour in juvenile European sea bass (Dicentrarchus labrax).

Accidental spills are pervasive pollution in aquatic ecosystems. Resorting to chemical dispersant is one of the most implemented strategies in response to oil spills, but it results in an increase in the bio-availability of oil compounds known to disturb fish neurosensory capacities and hence fish habitat use. While it has become well established that acute oil exposure can cause a range of physiological defects, sub-lethal consequences on animal behaviour have only received recent attention.