TY - JOUR T1 - Effects of Spawning Frequency and Density of Incubating Eggs on Egg and Larvae Survival Rates in Rainbow Trout TT - اثر دفعات تخم‌ کشی و تراکم نگهداری تخم بر میزان ماندگاری تخم و لارو در ماهی قزل‌ آلای رنگین کمان [ Oncorhynchus mykiss (Walbaum, 1792)] JF - JSTNAR JO - JSTNAR VL - 6 IS - 4 UR - http://jstnar.iut.ac.ir/article-1-150-en.html Y1 - 2003 SP - 219 EP - 230 KW - Broodstock KW - Rainbow trout KW - Survival rate KW - Spawning frequency. Density N2 - To determine the effects of spawning frequency and density of incubating eggs on the survival rates of eggs and larvae in rainbow trout, five different groups of broodstocks with varying spawning frequencies were stripped. After fertilization, the percentage of survival at different stages of development, from eying, hatching to free swimming fry stages and also growth rates of larvae were determined. Moreover, the effects of incubating egg density (4000, 7000, 10000 per tray) on the different developmental stages of egg through free swimming larvae for each group of broodstock was studied. The study was carried out in a completely randomized design as a 5*5*3 factorial arrangement with three replicates. The results indicated that survival and growth rates are significantly correlated with spawning frequency (P M3 ER -