Investigation of changes in biochemical and blood parameters of rainbow trout (Oncorhynchus mykiss) for breeding in saline water

Abstract The purpose of this study was to investigate the compatibility of rainbow trout fish with biochemical and blood parameters in waters with a salinity range of 0-20 gram per liter order to allow the introduction and development of this species in different aquatic environments with different salinity levels. Baby fish from a cold water factory in Mazandaran province were transported to the Caspian Sea Ecology Institute for testing. fishes with average weight 31.56 ± 0.70 g and mean fork length of 13.87 ± 0.15 cm, in 3 treatments in water with saline (fresh water, 13 and 20 g / l) With a density of 15fishes in, each 300 liter polyethylene tank containing 250 liters of tested water was introduced. Fresh water  water from the Tajan River and 13 grams per liters of water from the Caspian Sea and 20 grams per liters of water from Caspian Sea salt and sea salt water were prepared. Every day, 50 percent of the water tanks were replaced. The duration of the experiment was 7 days. Measurement of measured water parameters during the test period included: Oxygen dissolved in 6 mg / L, pH = 8.2, nitrite less than 0.1, nitrate less than 16 mg / l, ammonium 17.52 mg / l And a temperature of 15.5 ° C. In the experimental period, mortality were not observed in experimental groups. The results showed that relative osmolarity, sodium, chloride, magnesium, cortisol, calcium, hematocrit, hemoglobin, number of red blood cells and white in saline medium were higher than fresh water (p <0.05). The results of blood and blood ionisation of blood plasma of trout fish indicate the physiological compatibility of fish species with the changes in salinity and adaptability to provide the possibility of rearing these fish.