Effect of heat shock applied in different period on triploid formation and viability rate in rainbow trout (Oncorhynchus mykiss) eggs

In this study, effects to triploid percentage and survival ratio of thermal shock that applied to recently impregnated eggs of rainbow trout (Oncorhynchus mykiss) at different periods have been investigated. Application process realized 10 minutes later after the fertilization, thermal shock have been performed to O. mykiss eggs that getting by use of stripping for different time periods at 26°C for 5, 10, 15 and 20 minutes and eggs were separated to experimental groups with regard to these time periods. Survival ratio at the classical incubation situations, have been established throughout 60 days in control and experimental groups. Chromosome analysis results of eyed periods larvae of thermal shocked eggs were detected as diploid 2n=56 and triploid 3x=84. In addition, blood preparation were prepared with thin smear method and results of erythrocyte measurements were determined for creation of triploid percentage. As the result of 5, 10, 15, 20 min time periods thermal shocks, triploid percentages of experimental groups were detected as %10, %40, %90 ve %95 respectively. In the wide axis length of erythrocyte, cell and nucleus of 10, 15, 20 min thermal shocked groups, there were no statistically significant differences obtained according to control groups (p<0,05). In addition, survival ratio according to groups beginning from control groups according to thermal shock periods were appeared as %81,46, %75,55, %71,25, %66,01 and %55,76 respectively.In our study, O. mykiss eggs that thermal shocked at 26 °C for 15 and 20 minutes time periods were determined %90 and %95 triploid creation. When we consider survival rates, the most fine triploid product were obtained with % 59 and 15 minutes thermal shocked. In addition to, as the result of cell and nucleus of erythrocyte measurements, measurements of wide axis have been exhibited to triploid individuals.