Ahmad Gharaei; Abdolali Rahdari; Mostafa Ghaffari
Volume 10, Issue 1 , September 2012, , Pages 1-11
Abstract
This study was carried out to evaluate the use of synthetic hormones (ovaprim,hCG) to induce spawning of snow trout(Schizothorax zarudnyi) fish. Wild broods (45 females and 53 males 1328±45, 632±17.6 g, respectively) caught from Chanimeh reservoirs (Sistan, Iran) were transported to Zahak ...
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This study was carried out to evaluate the use of synthetic hormones (ovaprim,hCG) to induce spawning of snow trout(Schizothorax zarudnyi) fish. Wild broods (45 females and 53 males 1328±45, 632±17.6 g, respectively) caught from Chanimeh reservoirs (Sistan, Iran) were transported to Zahak Hatcheries Complex (Sistan Fishery Department). The brood fishes were randomly distributed among five treatment groups:1- females treated with quadruplet injections( 0.2, 0.5, 0.5 and 0.3 ml ovaprim/kg B. W.) every 24 hrs. Simultaneously to second injections males were injected with 0.3 ml Ovaprim/kg B. W. 2- Females were injected with combination of ovaprim(0.2, 0.5 and 0.5 ml/kg B. W.) and hCG 1000,2000,2000 IU/kg B.W) and simultaneously to the 2nd injection of females, males were injected with 0.3 ml/kg B. W. ovaprim and 1500 I.U. hCG/kg B. W. C). 3- In the third treatment females were injected with ovaprim plus hCG (0.2, 0.5, 0.5 and 0.3 ml/kg B. W. + 200, 400, 400 and 300 I. U. /kg B.W. respectively every 24 hours) and males received 0.3 ml/kg B.W. ovaprim + 200 I.U. hCG /kg B.W., at the second dose of females via injection. 4- In the fourth treatment females were injected triplet injections of different doses of hCG (400, 800 and 800 I.U. hCG/kg B.W.) every 24 hours and also males (500 I.U./kg B.W.) synchronized to second injections to females.5- Finally,in the fifth treatment 0.3 ml/kg B.W. saline was injected to all males and females belonging to control group. The results showed mean working fecundity for 1, 2, 3, 4 and 5 groups was 39531±7802, 18625±9704, 15682±5982, 0 and 0, respectively. Latency period was 36.2±3.77, 12.33±0.66 and 30.2±2.95, conversion percentage of dry egg to eyed egg was 88.97±0.9, 73.19±2.04 and 75.26±3.90, conversion percentage of eyed egg to larvae was 81.93±1.15, 75.67±0.19 and 71.03±1.03 for a, b and c groups, respectively. There were significant differences in the fecundity, latency period and other parameters mentioned above between the group treated with only ovaprim and the control group (P<0.05). Based on the results it could be concluded that treatment of Snow trout with ovaprim is effective for spawning induction.