مستخلص: |
In this study, the tolerable concentration of sodium chloride in juvenile kutum, Rutilus kutum and its effect on the fish gill, liver and kidney were examined. So, LC50 of sodium chloride in 96 h in a standing environment on 200 juveniles of 1-3 g was determined to be 8.12 g L-1 using Probit analysis statistical method. The experiment was performed according to the OECD method with five treatments and one control (each with three replications). Toxicity test was performed in 30-L glass aquariums. Ten juvenile kutum were stocked in each aquarium. LC10, LC50 and LC90 of sodium chloride for 96 h with logarithmically-determined concentrations (5, 6.46, 8.36, 10.81 and 14 g L-1, respectively) were 3.37, 8.12, 19.52 g L-1. During the experiment, water temperature (22 ± 0.7 °C), dissolved oxygen (7.5 ± 0.3 mg L-1) and pH (7.52 ± 0.2) were measured daily. Histopathological examination on kutum juveniles in the gill by the increased sodium chloride concentration, included hyperemia, hyperplasia, the secondary lamellae adhesion, cell necrosis and lifting secondary lamellar epithelial layers. In addition, hyperemia and fat degeneration, cell necrosis, bleeding and hypertrophy were observed in the fish liver. Histopathologically, hemorrhage, cell necrosis, hemorrhage, melanoma macrophages and increased urinary space were observed in the fish kidneys. Behaviorally, group swimming and aggregating at the corners of aquariums and floors, and by elevating the sodium chloride concentration, impatience and suffocation of fish increased. In addition, by uprising the sodium chloride concentration, lethargy and mucus secretion on the surface of juvenile fish body increased. [ABSTRACT FROM AUTHOR] |