Effects of polyploidy induction on growth performance, survival ‎rate, and ‎erythrocyte of rainbow trout (Oncorhynchus mykiss)‎

In this study, rainbow trout diploid, triploid, and tetraploid were comparatively investigated regarding the growth ‎performance, survival rate, and erythrocyte characteristics. For the triploid production, the fertilized eggs received 26.5 ℃ ‎thermal shock under three treatments: 1. double 1-min shock after 15 and 30 min of the fertilization, 2. one 15-min shock ‎after 15 min of the fertilization, and 3. one 12-min shock after 20 min of the fertilization. Tetraploidy was induced by ‎application of 28 ℃ thermal shock under three treatments: 1. 10-min shock after 59 degree-hours of the fertilization, 2. 10-‎min shock after 66 degree-hours of the fertilization, and 3. 10-min shock after 72 degree-hours of the fertilization. The best ‎triploidization results, 66.6% survival rate and 87% triploidization rate, achieved by application of 12-min shock after 20 ‎min of the fertilization. The best tetraploidization results, 54.9% survival rate and 7.94% triploidization rate, achieved by ‎application of 10-min shock after 59 degree-hours of the fertilization. There were no significant differences between the ‎triploid and diploid fish, wheras the tetraploids showed significantly lower growth rate than the diploids. In conclusion, in ‎this study, triploid and tetraploid production of rainbow trout were improved, and application of erythrocyte cell size as a ‎reliable and efficient polyploidy detection method was emphasized.‎