Browsing by Subject "Dicentrarchus labrax"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Publication
    Open Access
    Effects of water salinity on melatonin levels in plasma and peripheral tissues and on melatonin binding sites in European sea bass (Dicentrarchus labrax)
    (Elsevier, 2009) López Olmeda, José Fernando; Oliveira, Catarina; Kalamarz, Hanna; Kulczykowska, Ewa; Delgado, María Jesús; Sánchez Vázquez, Francisco Javier; Fisiología
    Sea bass is a euryhaline fish that lives in a wide range of salinities and migrates seasonally from lagoons to the open sea. However, to date, the influence of water salinity on sea bass melatonin levels has not been reported. Here, we evaluated the differences in plasma and tissue melatonin contents and melatonin binding sites in sea bass under four different salinities: seawater (36 ‰), isotonic water (15 ‰), brackish (4 ‰) and freshwater (0 ‰). Melatonin content was evaluated in plasma, whole brain, gills, intestine and kidney, while melatonin binding sites were analyzed in different brain regions and in the neural retina. Plasma melatonin levels at mid-dark varied among salinities, with the lowest value occurring at seawater salinity (102 pg/ml), and the highest at freshwater (151 pg/ml). In gills and intestine, however, the highest melatonin values were found in the seawater group (209 and 627 pg/g tissue, respectively). Melatonin binding sites in the brain also varied with salinity, with the highest density being observed at the lower salinities in optic tectum, cerebellum and hypothalamus (30.3, 13.0, and 8.0 fmol/mg protein, respectively). Melatonin binding sites in the retina showed a similar pattern, with the highest values in the fish maintained in freshwater. Taken together, these results revealed that salinity influences melatonin production and modifies the density of binding sites, which would point to a role for this hormone in timing seasonal events in sea bass, including those linked to fish migration between waters of different salinities.
  • Repository logo
    Publication
    Open Access
    Erythrocyte phagocytosis in gilthead seabream (Sparus aurata) and European sea bass (Dicentrarchus labrax).
    (2024-11-04) Campos Sánchez, Jose Carlos; Guardiola, Francisco A.; Meseguer, José; Esteban Abad, María Ángeles; Biología celular e Histología
  • Thumbnail Image
    Publication
    Embargo
    Evolution of Biometric Indices and Plasma Metabolites During Prolonged Starvation in European Sea Bass (Dicentrarchus labrax, L.)
    (1997) Echevarría, Germán; Martínez-Bebia, Manuel; Zamora, S.; Tecnología de Alimentos, Nutrición y Bromatología
    Taking as criteria plasmatic urea profiles, and percentage losses over time in weight and in condi tion 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 men tioned 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. comp biochem physiol 118A;1:111–123, 1997.  1997 Elsevier Science Inc.
  • Repository logo
    Publication
    Open Access
    Similarities between the lipid profiles of skin and liver of European Sea Bass (Dicentrarchus labrax) fed diets with different lipid content
    (Springer, ) Espinosa-Ruiz, Cristóbal; González-Silvera, Daniel; Esteban Abad, María Ángeles; Biología celular e Histología
    The specific fatty acid profile of fish can vary depending on species, age, diet and other factors. However, in general, fish are generally rich in long-chain polyunsaturated fatty acids (LC-PUFA), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Liver, skin, meat and fish mucus can contain different levels and types of fatty acids. In fact, each of these tissues can provide valuable information about the fatty acid profile of the whole fish. In order to establish a non-invasive method to assess the lipid profile of fish tissues, twenty-four European sea bass (Dicentrarchus labrax) were fed two different diets [containing different PUFAs profiles] for 30 days. Samples of cutaneous mucus, skin, flesh and liver were then obtained and their fatty acid profile was analyzed by gas chromatography. Multidimensional scaling (MDS), SIMPER procedure (similarity percentages) and permutation test (PERMANOVA) were performed. The results indicate that there are similarities in the fatty lipid profile of skin and liver, as well as between skin and liver mucus. Relationships have been observed between the fatty acid compositions of the different fish tissues, in particular between liver and skin, where linoleic acid (18:2n-6) is the most significant, which would allow the skin to be used as a proxy to infer the hepatic lipid profile, without the need to sacrifice the animals