Effects of different levels of dietary prebiotic Immunogen on reproductive performance of angelfish (Pterophyllum scalare) breeders and larval survival resulting in a sudden increase of temperature stress

In this research, the effects of different levels of prebiotic Immunogen on reproductive performance of angelfish (Pterophyllum scalare) were investigated. 16 pairs of angelfish breeders with average weight 8.67±033 were fed till saturating for 50 days and after this period, reproductive indices such as absolute fecundity, hatching percent, larval survival until yolk-sac absorption, gonadosomatic index and larval tolerance against high temperature stress to amount 10 °C were evaluated. The experiment was carried out in completely randomize design with four levels 0 (control), 1% (T1), 1.5% (T2) and 2% (T3) that each treatment had 3 replications. Amount of absolute fecundity in T2 significantly was higher than control (p0.05). Gonadosomatic index in T2 and T3 was upper than control and T1 that this difference was significant (p0.05). Regarding to findings of this research, addition prebiotic Immunogen at level of 1.5% to angelfish breeder's diet was recommended for reproductive indices promotion.