Effects of chronic ammonia exposure on ammonia metabolism and excretion in marine medaka Oryzias melastigma.

摘要: Abstract Ammonia is highly toxic to aquatic organisms, but whether ammonia excretion or metabolism less compounds the major strategy for detoxification in marine fish against chronic exposure unclear date. In this study, we investigated and of medaka Oryzias melastigma during exposure. The were exposed 0, 0.1, 0.3, 0.6, 1.1 mmol l−1 NH4Cl spiked seawater 8 weeks. Exposure 0.3–1.1 mmol l−1 NH4Cl had deleterious effects on fish, including significant reductions growth, feed intake, total protein content. However, could take strategies detoxify ammonia. tissue (TAmm) treatments was significantly higher than those 0 0.1 mmol l−1 NH4Cl after 2 weeks exposure, it recovered with prolonged time, ultimately reaching control level amino acid catabolic rate decreased reduce gross production increasing ambient concentration. concentrations most metabolites remained constant 0–0.6 mmol l−1 NH4Cl treatments, whereas 5 acids 3 energy metabolism-related treatment. JAmm steadily increased from 0.6 mmol l−1 slightly when concentration 1.1 mmol l−1. Overall, cope sublethal environment by regulating TAmm via reducing excretion.