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- Changes in plasma amino acid levels in a euryhaline fish exposed to different environmental salinitiesPublication . Aragão, C.; Costas, B.; Vargas-Chacoff, L.; Ruiz-Jarabo, I.; Dinis, Maria Teresa; Mancera, J. M.; Conceição, L. E. C.Previous studies have shown that Senegalese sole is partially euryhaline in the juvenile phase, being able to adapt to a wide range of salinities in a short-time period, due to changes at the osmoregulatory and metabolic level. This study aimed to assess the effects of acclimation of sole to a wide range of salinities, with a special emphasis on the role of plasma amino acids during this process. Sole juveniles were acclimated for 2 weeks to different salinities: 5, 15, 25, 38, and 55 g L−1. Plasma levels of cortisol, glucose, osmolality, and free amino acids were assessed at the end. Changes in plasma levels of cortisol, glucose, and amino acids indicate that fish reared at 5 and 55 g L−1 were facing extra energy costs. Amino acids seem to play an important role during salinity acclimation, either as energy sources or as important osmolytes for cell volume regulation.
- Stress response and changes in amino acid requirements in Senegalese sole (Solea senegalensis Kaup 1858)Publication . Aragão, C.; Corte-Real, Joana; Costas, B.; Dinis, Maria Teresa; Conceição, L. E. C.Fish in aquaculture are often exposed to various stressors that may change their ability to survive or limit growth. Amino acids are used for processes other than growth, including stress response. This study intended to analyse how repeated acute handling stress can affect growth and amino acid requirements in fish. Senegalese sole juveniles were weekly held in the air during 3min (Handling) for 9 weeks; Control groups were left undisturbed. Growth and plasma levels of stress indicators and of free amino acids were assessed at the end of the experiment. Plasma cortisol and osmolality levels showed that fish in the Handling treatment were stressed, but growth was unaffected. Plasma amino acid concentrations indicate that their requirements in stressed fish were altered, which probably reflects the synthesis of proteins or other specific compounds related to stress response.
- Feed deprivation in Senegalese sole (Solea senegalensis Kaup, 1858) juveniles: Effects on blood plasma metabolites and free amino acid levelsPublication . Costas, B.; Aragão, C.; Ruiz-Jarabo, I.; Vargas-Chacoff, L.; Arjona, F. J.; Dinis, Maria Teresa; Mancera, J. M.; Conceição, L. E. C.The effects of prolonged feed deprivation were assessed on blood plasma metabolites and free amino acid levels in Solea senegalensis. Juvenile specimens were maintained at two experimental conditions (24 h fasted and 21 days feed-deprived). In feed-deprived fish, relative growth rate and hepatosomatic index as well as plasma triglycerides and proteins levels were significantly lower.