Percorrer por autor "Faria, Ana Margarida"
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- Differential effects of food restriction and warming in the two-spotted goby: impaired reproductive performance and stressed offspringPublication . Lopes, Ana F.; Murdoch, Robyn; Martins-Cardoso, Sara; Madeira, Carolina; Costa, Pedro M.; Félix, Ana S.; Oliveira, Rui F.; Bandarra, Narcisa M.; Vinagre, Catarina; Lopes, Ana R.; Gonçalves, Emanuel J.; Faria, Ana MargaridaClimate change is a growing threat to marine organisms and ecosystems, and it is already modifying ocean properties by, for example, increasing temperature and decreasing pH. Increasing water temperature may also lead to an impairment of primary productivity and an overall depletion of available zooplankton. Understanding how the crossover between warming and zooplankton availability impacts fish populations has paramount implications for conservation and mitigation strategies. Through a cross factorial design to test the effects of ocean temperature and food availability in a temperate marine teleost, Pomatochistus flavescens, we showed that hindered feeding impacted sheltering and avoidance behaviour. Also, low food availability impaired fish reproduction, particularly male reproduction, as the expression of cyp11b1, a gene with a pivotal role in the synthesis of the most important fish androgen, 11-ketotestosterone, was significantly reduced under a low food regime. In contrast, temperature alone did not affect reproductive success, but offspring showed increased saturated fatty acid content (embryos) and increased lipid peroxidation (larvae). Altogether, food availability had a stronger effect on fitness, showing that coping with elevated temperatures, an ability that may be expected in shallow-water fish, can be indirectly impacted, or even overwhelmed, by the effects of ocean warming on primary productivity and downstream ecological processes.
- Thermal performance of early stages of Sparus aurata integrating body condition, behavior and physiological responsesPublication . Almeida, João Carlos; Costa, Ana Beatriz; Ozkan, Buzenur; Martins-Cardoso, Sara; Maulvault, Ana Luísa; Pousão-Ferreira, Pedro; Ribeiro, Laura; Lima, André Ricardo Araújo; Faria, Ana Margarida; Lopes, Ana RitaTemperature has a profound impact on fish, particularly during the early life stages (ELS), when they exhibit a narrower range of thermal tolerance compared to later developmental phases. This study investigated the long-term effects of temperature on Sparus aurata ELS that were exposed to four temperature regimes for 11 weeks: 19 °C, 22 °C, 24 °C and 28 °C. Parameters evaluated included growth, Fulton’s condition factor, behavior (risk-taking, activity and aggressiveness), routine metabolic rate (RMR), metabolic enzyme activity (citrate synthase and lactate dehydrogenase) and oxidative stress biomarkers (Lipid Peroxidation, Catalase and Glutathione-S-Transferase). Growth and condition were highest at 28 °C and lowest at 19 °C. While risk-taking behavior was unaffected by temperature, aggressiveness increased at 24 °C and 28 °C. Swimming activity increased from 22 °C to 28 °C, but RMR remained stable. Antioxidant enzyme activity increased in the brain and gills at 28 °C, but no signs of Lipid Peroxidation were found. Physiological biomarkers accounted for over 67% of trait variability. These findings suggest that S. aurata ELS adopt temperature-specific physiological strategies, such as upregulating metabolic enzymes at lower temperatures to sustain body condition and enhancing antioxidant defenses at higher temperatures to counteract oxidative stress. Thus, ELS can maintain physiological performance across a broad thermal range, albeit with acclimatize trade-offs.