Iranian Biology Society Journal of Animal Research (Iranian Journal of Biology) 2383-2614 28 2 2015 06 22 Effect of out-of-season spawning on semen quality indices and fertilization success in rainbow trout (Oncorhynchus mykiss( Effect of out-of-season spawning on semen quality indices and fertilization success in rainbow trout (Oncorhynchus mykiss( 256 262 709 FA Fardin Shaluei Tayebeh Hosseini Mohammad Reza Iman Pour Journal Article 2011 03 27 Some biological aspects of semen were investigated in the rainbow trout (Oncorhynchus mykiss( during the out-of-season spawning, by determination of spermatological parameters, seminal plasma indices (ionic and organic composition) and fertilization success. The concentrations of Sodium (Na+), Potassium (K+), Calcium (Ca2+), Magnesium (Mg2+) and Chlorine (Cl-) ions were 60.87±28.22, 36.56±13.69, 4.33±1.19, 3.08±.88 and 71.96±27.60 MmL-1 respectively. Seminal plasma contained 0.26±0.13 g/dl protein, 2.69±1.54 mg/dl cholesterol, 2.33±0.86 mg/dl glucose, 6.46±2.45 mg/dl triglyceride and 11.04±9.31 mg/dl urea. The pH of seminal plasma increased from 6.72±0.32 in spawning season to 7.16±0.26 during the out-of-season spawning (P<0.01). But Semen spermatocriet, seminal plasma Calcium (Ca2+) and Chlorine (Cl-) ion concentrations and cholesterol level decreased significantly during the out-of-season spawning (P<0.01). Spermatozoa concentration and triglyceride level also declined significantly during the out-of-season spawning (P<0.05). Semen volume, movement duration, fertilization success, Sodium, Magnesium and Potassium ion concentrations, glucose, protein and urea levels did not show significant differences between reproductive season and out-of-season spawning (P>0.05). In the present study spermatological parameters, seminal plasma indices and fertilization success were investigated in reproductive season and out-of-season spawning. Although some spermatological parameters and seminal plasma indices altered during out-of-season spawning, but significant difference on fertilization success was not observed. Some biological aspects of semen were investigated in the rainbow trout (Oncorhynchus mykiss( during the out-of-season spawning, by determination of spermatological parameters, seminal plasma indices (ionic and organic composition) and fertilization success. The concentrations of Sodium (Na+), Potassium (K+), Calcium (Ca2+), Magnesium (Mg2+) and Chlorine (Cl-) ions were 60.87±28.22, 36.56±13.69, 4.33±1.19, 3.08±.88 and 71.96±27.60 MmL-1 respectively. Seminal plasma contained 0.26±0.13 g/dl protein, 2.69±1.54 mg/dl cholesterol, 2.33±0.86 mg/dl glucose, 6.46±2.45 mg/dl triglyceride and 11.04±9.31 mg/dl urea. The pH of seminal plasma increased from 6.72±0.32 in spawning season to 7.16±0.26 during the out-of-season spawning (P<0.01). But Semen spermatocriet, seminal plasma Calcium (Ca2+) and Chlorine (Cl-) ion concentrations and cholesterol level decreased significantly during the out-of-season spawning (P<0.01). Spermatozoa concentration and triglyceride level also declined significantly during the out-of-season spawning (P<0.05). Semen volume, movement duration, fertilization success, Sodium, Magnesium and Potassium ion concentrations, glucose, protein and urea levels did not show significant differences between reproductive season and out-of-season spawning (P>0.05). In the present study spermatological parameters, seminal plasma indices and fertilization success were investigated in reproductive season and out-of-season spawning. Although some spermatological parameters and seminal plasma indices altered during out-of-season spawning, but significant difference on fertilization success was not observed. https://animal.ijbio.ir/article_709_1ecfb463472ec9115b10c292ef8bc986.pdf