Evolution of biometric indices and plasma metabolites during prolonged starvation in European sea bass (Dicentrarchus labrax, L)

Taking as criteria plasmatic urea profiles, and percentage losses over time in weight and in condition factor, the process of starvation (up to 150 days) in European sea bass (Dicentrarchus labrax) divides into two phases. In the first phase (up to 50 days), there is no variation in the concentration of urea, the percentage losses in condition factor are greater than those in weight, intestinal fats are exhausted, premature involution of gonadal tissue occurs, there is no variation in the chemical composition of white muscle, and proteinaemia decreases. In the second phase, there is an increase of 237% in the concentration of urea, percentage losses in weight predominate over those in the condition factor, the moisture in white muscle increases, while ash reduces, and proteinaemia returns to its initial values. Of all the plasma free amino acids measured, only Arginine falls dramatically during the onset of starvation and, after stabilizing, there is the significant increase in urea mentioned above. Plasma concentration of NH3 remained constant throughout the experimental period. Significant variations in plasmatic Alanine were not detected. Concentrations of plasma Taurine remained high during the whole of the second phase. (C) 1997 Elsevier Science Inc.