Document Type : Research Paper
Authors
1
Ph.D. Student in Propagation and Rearing of Aquatic Animal, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
2
Assistant Professor in Biotechnology and Genetics Department, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
3
Professor in Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran
4
Assistant Professor in Biotechnology and Genetics Department, International Sturgeon Research Organization of the Caspian Sea, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
5
Associate Professor in Aquaculture Department, International Sturgeon Research Organization of the Caspian Sea, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
Abstract
This study was done to determine the role of sperm on the fertilization and hatching rates in Persian sturgeon (Acipenser persicus). For this purpose, the sperms of three males fertilized ova of three females using 3×3 factorial design. Sperm motility and density, spermatocrit percent, sperm pH and osmolarity and ovum number per grams, micropyle number and diameter were measured. 1mL of sperm from each male was fertilized 100g of ova from each female. Therefore, 9 treatments including F1M1, F1M2, F1M3, F2M1, F2M2, F2M3, F3M1, F3M2 and F3M3 were designed (triplicate). The percentage of fertilization was determined 5 hours after fertilization and hatching rate was determined after 6 days. The results showed that the average number of micropyle pores in ova were 6, 8 and 9, respectively in Acipenser persicus. The sperm motility was 50, 60 and 80 percent, respectively. F3M3 treatment showed the highest percentage of fertilization and larvae hatching rate. F3M1 treatment had the lowest percentage of fertilization and F1M1 treatment had the lowest hatching rate. The results of measuring male sperm parameters showed that the high density of sperm with the number of ovum micropyles to increase fertilization, was unrelated and there was no significant difference between fertilization rate with the number of micropyles and measured parameters in sperms (P>0.05). Based on the Pearson correlation coefficient relationship, there were negative between sperm density with fertilization (r = -0.603, P<0.01) and hatching (r = - 0.175, P<0.01) rates. There was a positive relationship between the number of micropyle and fertilization rate (r = 0.574, P<0.01) and between the osmolarity and fertilization (P <0.01, r = 0.511) and hatching (P <0.01, r = 0.288) rates. Due to the large numbers of micropyle in sturgeon eggs, to increase the percentage of fertilization rate, sperm density should be low but motility duration and quality should be high.
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