Browsing by Subject "Salinity"

Now showing 1 - 3 of 3
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    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.
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    Influence of soil properties on plant density and species richness of saline desert
    (Universidad de Murcia, 2016) Pilania, Pradeep Kumar; Panchal, Nilesh Sundarjibhai
    Influencia de las propiedades del suelo en la densidad de plantas y la riqueza de especies de desierto salino El ambiente edáfico tiene una significativa influencia en la productividad. La salinidad es uno de los principales factores que afectan negativamente a la vegetación. Se estudió un ecosistema desértico de la India (Pequeño Rann de Kutch; 7020 ha) para medir la influencia de las propiedades del suelo en la vegetación. Tanto la riqueza de especies (SR) como la densidad de hierbas y arbustos/árboles (17.018 plantas m-2 y 8.617 plantas 10 m-2) fueron mayores en el punto 4, con valores altos de OC, OM, N, P, Ca y Fe (0.684, 1.179, 0.059 %, 42.338 kg ha-1, 170.732, 32.016 mg kg-1) y bajos niveles de arcilla, EC y Na (33.654%, 9.441dSm-1 y 68.699 mg kg-1). Valores altos de arcilla, Na y EC con bajo Ca y Fe resultaron en bajas densidades de SR (lugares 2 y 5). Las bajas SR y densidad se deben a bajas concentraciones de OC, OM, N, P, Fe, Ca y alta concentración de arcilla, Na y EC.
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    Ochthebius (s.str.) caudatus Frivaldszky, 1883: redescription, new records, and group assignation based on molecular data (Coleoptera: Hydraenidae).
    (2019) Jäch, M.A.; Delgado, Juan. A.; Twardy, A.; Villastigo, A.; Dorfer, W.; Zoología y Antropología Física
    The halobiontic Ochthebius (s.str.) caudatus F RIVALDSZKY , 1883 is redescribed and recorded from Poland for the first time. Based on molecular data it is assigned to the O. marinus group. Its ecology is briefly described.