University of Guilan Aquatic Physiology and Biotechnology 2345-3966 2 3 2015 10 23 Effects of sublethal contractions of Fenpropathrine pestiside on serum Na+, K+ and cortisol of common carp (Cyprinus carpio) Effects of sublethal contractions of Fenpropathrine pestiside on serum Na+, K+ and cortisol of common carp (Cyprinus carpio) 1 12 1334 FA Mohsen Jafarinejad Majid Askari Hesni 0000-0001-9309-2212 Akbar Karimi Narges Amrollahi Biuki Mina Motamedi Journal Article 2015 10 27 The study of the influence of serum indices can be a good indicator to assess the toxicity of pesticides in the environment. In this study, the effects of Fenpropathrine on plasma Na⁺, K⁺ and cortisol level of common carp, <em>Cyprinus carpio</em> was investigated. The acute toxicity concentration (LC₅₀) was determined for 96 hours according to O.E.C.D (1989) standard method. Then fish specimens were exposed to 5, 10 and 20% of LC₅₀ (14µg/l) and also control group with three replicates. In each treatment, 54 healthy fish specimens (mean standard length: 7.8±0.6cm; mean weight: 10±1.2 g) were used. Sub lethal experiment was conducted for a period of 14 days and blood sampling was collected at 1, 7 and 14th day post exposure time. Plasma Na⁺, K⁺ and cortisol levels were measured. The results show that plasma K⁺ levels of the exposed specimens increased and levels of plasma Na⁺decreased significantly. Plasma cortisol levels increased in all treatments compared to control during the first day, and then decreased gradually. In conclusion, Fenpropathrine have direct effect on common carp stress and osmoregulation mechanisms. The study of the influence of serum indices can be a good indicator to assess the toxicity of pesticides in the environment. In this study, the effects of Fenpropathrine on plasma Na⁺, K⁺ and cortisol level of common carp, <em>Cyprinus carpio</em> was investigated. The acute toxicity concentration (LC₅₀) was determined for 96 hours according to O.E.C.D (1989) standard method. Then fish specimens were exposed to 5, 10 and 20% of LC₅₀ (14µg/l) and also control group with three replicates. In each treatment, 54 healthy fish specimens (mean standard length: 7.8±0.6cm; mean weight: 10±1.2 g) were used. Sub lethal experiment was conducted for a period of 14 days and blood sampling was collected at 1, 7 and 14th day post exposure time. Plasma Na⁺, K⁺ and cortisol levels were measured. The results show that plasma K⁺ levels of the exposed specimens increased and levels of plasma Na⁺decreased significantly. Plasma cortisol levels increased in all treatments compared to control during the first day, and then decreased gradually. In conclusion, Fenpropathrine have direct effect on common carp stress and osmoregulation mechanisms. https://japb.guilan.ac.ir/article_1334_230807451216ec4eba3d6f882d0a89d6.pdf