Acute exposure of Siberian sturgeon (Acipenser baeri, Brandt) yearlings to nitrite: median-lethal concentration (LC50) determination, haematological changes and nitrite accumulation in selected tissues

• Published in: Aquatic Toxicology
• Main Authors: Huertas, M., Gisbert, E., Rodriguez, A., Cardona, L., Williot, Patrick, Castello Orvay, F.
• Other Authors: UNIVERSITAT DE BARCELONA ESP, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Ressources aquatiques continentales (UR RABX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2002
• Subjects: [SDE]Environmental Sciences; Siberian sturgeon
• Online Access: https://hal.inrae.fr/hal-02580438; https://doi.org/10.1016/S0166-445X(01)00207-7

International audience Exposure of Siberian sturgeon (Acipenser baeri) yearlings (172.0±18 g; mean±S.D.) to several NO2-¯N concentrations (0, 25, 130, 180 and 275 mg/l) was studied for 72 h in static tests. At 72 h, the median-lethal concentration of NO2-¯N was 130 mg/l in water with high chloride content (130.5 mg/l). Nitrite exposure produced high levels of methaemoglobin (MetHb) but did not seem to cause mortality, as surviving fish showed higher levels (82.7±5.6%) than torpid specimens (60.8±4.5%). Levels of MetHb were unrelated to environmental and plasmatic nitrite concentrations, as both torpid and surviving fish exposed to the highest nitrite levels (275 mg/l of NO2-¯N) presented similar concentrations of MetHb to those exposed to 25 mg/l of NO2-¯N, thus indicating the ability of Siberian sturgeon yearlings to regulate plasmatic nitrite levels and maintain them lower than the environmental concentration of the toxicant. Nitrite exposure caused changes in the plasmatic electrolyte balance, which is characterised by extracellular hyperkalemia, high plasmatic chloride levels and low plasmatic sodium concentration. Differences between the nitrite concentration in the liver of torpid (46.3±9.0 mg/l) and surviving specimens (19.1±13.1 mg/l) exposed to several concentrations of NO2-¯N suggest a significant contribution of the liver in nitrite detoxification pathways, and would thus explain a possible nitrite tolerance of Siberian sturgeon yearlings. Cette étude montre la capacité des esturgeon de Sibérie d'un an à réguler les niveaux de nitrite plasmatique et les maintenir plus bas que la concentration de l'élément toxique dans l'environnement, ainsi que le rôle du foie de ces poissons et cherche à expliquer sa probable tolérance au nitrite.