58 JUNE 2013 • WORLD AQUACULTURE • WWW.WAS.ORG TABLE 4. Characteristic of males of River Don sterlet broodstock that are formed from fry (generation of 2005 year). Age Weight, kg Length, cm Ejaculate Relative ejaculate volume, ml volume ml/kg of weight 3+ 0.90±0.07 59.3±1.6 20.2±2.1 22.4±1.5 4+ 1.06±0.14 60.2±1.7 22.2±1.5 21.0±1.5 5+ 1.36±0.21 61.4±1.6 28.4±2.2 20.9±2.0 TABLE 5. Characteristic of males of River Don sterlet broodstock that are formed from breeders (generation of 2006 year). Age Weight, Length, Ejaculate Relative ejaculate kg cm volume, ml v ml/kg of weight 4+ 1.26±0.13 62.0±1.7 26.4±2.2 21.0±1.5 5+ 1.35±0.20 63.2±1.9 33.0±1.5 24.5±1.8 6+ 1.52±0.24 65.1±1.9 42.2±1.8 24.8±1.9 TABLE 3. Characteristic of females of River Don sterlet broodstock that are formed from breeders (generation of 2006 year). Age Weight, kg Length, cm Work fecundity Relative fecundity Spawning interval (thousand pieces) (thousand pieces/ kg of weight) (months) 4+ 1.25±0.11 62.8±1.7 24.9±1.6 19.9±1.9 8.0 5+ 1.46±0.13 66.2±1.3 30.5±2.1 20.9±1.7 7.8 6+ 1.65±0.16 68.1±1.3 35.4±1.8 21.5±1.7 7.5 TABLE 6. Quality of cryopreserved sperm. Characteristics Native sperm Cryopreserved sperm Spermatozoa activity (%) 100 70 Fertilization rate (%) 90 80 Amount of fingerlings (%) 75 60 TABLE 2. Characteristic of females of River Don sterlet broodstock that are formed from fry (generation of 2005 year). Age Weight, kg Length, cm Work fecundity Relative fecundity Spawning interval (thousand pieces) (thousand pieces/ kg of weight) (months) 3+ 0.97±0.08 60.2±1.6 15.5±1.5 15.9±1.6 9.0 4+ 1.09±0.16 62.3±1.7 22.7±1.9 20.8±1.6 8.0 5+ 1.38±0.20 65.1±1.7 36.3±1.5 26.3±2.2 7.5 TABLE 1. Duration of spawning intervals of sterlet broodstock that was formed in recirculation system. Sex First spawning interval (month) Second spawning interval (month) Third spawning interval (month) 1 2 1 2 1 2 STERLET OF VOLGA RIVER ♀ 11 12 9 9.5 7 7.5 ♂ 10 11 8 9 6.5 6 STERLET OF DON RIVER ♀ 10 11 8 9 6 6.5 ♂ 9 10 9 10 5.5 6
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