TY - JOUR JF - nbr JO - NBR VL - 2 IS - 2 PY - 2015 Y1 - 2015/9/01 TI - Long time effect of oral cortisol on resistant to salinity changes in Common Carp (Cyprinus carpio Linnaeus, 1758) fingerling TT - اثر بلندمدت کورتیزول خوراکی بر مقاومت به تنش شوری در بچه‌ماهیان کپور معمولی ( Cyprinus carpio Linnaeus, 1758) N2 - Cortisol is a corticosteroid hormon which has important effects on osmoregulation in marine fish. In this study the effect of oral cortisol on resistance (salinity stress in 12ppt during 7 days) in common carp (cyprinus carpio) fry was investigated. For this purpose, common carp (1.36±0.12 gr) was distributed in 3 treatments and 1 control group in 3 replicates and fed with commercial food containing 0 (control), 50, 100 and 200 mg kg-1 food hydrocortisone during 8 weeks. At the end of the trial, hematocrit, biochemical blood parameters (glucose, calcium and total protein) and resistance of fish were determined. The results showed no significance in survival rates between treatments (p>0.05). Glucose levels in the control treatment was significantly lower than other treatments at the end of the trail by serological investigation (p<0.05). Fish were let in salinity stress and after 7 days all treatments showed a significant increase in the value of glucose (p<0.05). The highest value of glucose was observed in fish on fed 100 and 200mg hydrocortisone per kg-1 food )73.04±1.40) (p<0.05) and the highest level of haematocrit was observed after stress in the control group (61.67±2.08) (p<0.05). Calcium Ionic factor showed a significant increase in all treatments except for the control treatment (11.17±0.31) (p<0.05) and the highest value was observed in fish fed 200 mg hydrocortisone per kg-1. Total protein in fish treat-cortisol was significantly lower than the control group (p<0.05). The results of this study showed that oral administration of cortisol can improve the salinity resistance in the common carp fry SP - 103 EP - 112 AU - Beikazade, Azar AU - Imanpour, Mohammadreza AU - Taghizade, Vahid AD - Gorgan University of Agricultura l Sciences and Natural Resources , KW - cortisol KW - glucose KW - salinity stress KW - osmoregulation KW - common carp UR - http://nbr.khu.ac.ir/article-1-2493-en.html DO - 10.21859/acadpub.nbr.2.2.103 ER -