Effect of Striping Frequency in different ages males in Rainbow Trout (Oncorhynchus mykiss) on Sperm motility, Spermatocrit and Eyed Eggs Stage
Subject Areas : New Technologies in Aquaculture Development
Keywords: sperm, Oncorhynchus mykiss, Keywords: Motility, Spermatocrit, Striping Frequency,
Abstract :
Abstract This research has been conducted in the conservation center of Shahid Bahonar-Kelardasht for two months in 1387.To this purpose, 9 brood stocks from 3 different age levels (i.e. 2+, 3+, & 4+) were taken for the study. Three groups, considering their striping frequency, were placed in each age-based category. Male brood stocks were striped in three groups at weekly (8 times in duration), 10 days (6 times in duration) and 2 weeks (4 times in duration) intervals, respectively. The resuls showed that spermatocrit in males with the age of 2+ in every 10 days and every two weeks striping doesn't have a significant difference and the highest amount is (44.16±0.76%) and (46.16±0.76%) respectively. Spermatocrit in the 3+ age level showed a significant difference. In this case, the highest of spermatocrit was produced by the two- week striping (i.e. 46.16±0.76%). Spermatocrit was in its highest level in different groups of males with the age of 4+ whose striping interval was every 10 days and every 2 weeks which was (39±1.32%) and (40.16±1.04%) respectively. There was no significant difference in 2 groups. Duration of sperm motility in different groups of males with the age of 2 + showed nonsignificant difference but those in 3+ age group with weekly striping had the highest motality (i.e. 26±0.5 sec ). Duration of sperm motility was in the highest mode in the groups with the age of 4+ ,by weekly and 10 days striping interval, (28±1.2 sec) and (27.16±0.28 sec) respectively. In different groups under the 2+ age category eyed eggs stage showed no significant difference (p>0/05). Eyed eggs stage in males with the age of 3 + with every ten days and every two weeks striping intervals was the highest and showed no significant difference. The highest of eyed eggs stage in age 4 +was by 10 days and 2 weeks striping interval, (78±1%) and (80±1%) respectively. Comparing the groups, spermatocrit was in its highest range in every two weeks striping and lowest in weekly striping interval. The highest sperm motility was in weekly striping, but in eyed eggs stage it happened in every two weeks striping. Final conclusion confirmed that the best of brood stock male's age is 2+ and 3+ for fertilization. The best of striping Frequency by 10 days and 2 weekly. Final conclusion confirmed that the best age for fertilization in male brood stock is in theage of 2+ and 3+; the best striping frequency is every 10 days and every two weeks.
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