Study on effect of nutrition on amount of survival Salmo trutta caspius larvae nutrition with capsulated cyst Artemia urmiana

This research investigates the effect of Artemia urmiana replacement in Salmo trutta caspius larvae feeding on its survival index. The present study was carried out in a complete randomized design with four dietary groups including: treatment1 (control diet with commercial formulation), treatment 2 (diet with 25% decapsulated Artemia cyst and 75% concentrate), treatment 3 (diet with 50% decapsulated Artemia cyst and 50% concentrate), treatment 4 (75% decapsulated Artemia cyst and 25% concentrate) to final weight of1 gram. This experiment was performed in 4 sectioned trays, each divided into three equal parts with a fine metal mesh net and 300 larvae per part with 2 replicates and a total of 900 larvae. The larvae were prepared from the propagation center of Kelardasht .They were firstly weighed accurately and their average weight and biomass in each treatment was determined. The mean initial weight of larvae was 25 ± 120 mg, respectively. During the experiment, the survival rate (SR) was calculated. Comparison of mean (± SD) of survival percentage of the experimental groups showed that treatment 2 with 98.71 ± 19.19% and treatment 1 with 86.83 ± 1.21% had the highest and lowest survival rates, respectively. Comparison of this index in treatments 2 to 4 showed no significant difference (p> 0.05), but there was a significant difference compared to treatment 1 (p <0.05). According to the results of this study, it can be concluded that feeding with decapsulated A.urmiana cyst significantly reduces the mortality rate of S.trutta caspius larvae.