Enrichment of Artemia nauplii with essential fatty acids and vitamin C: effect on rainbow trout (Oncorhynchus mykiss) larvae performance

The effect of essential fatty acids (efa) and vitamin c-enriched artemia nauplii on growth, survival, and resistance to temperature (high) stress in rainbow trout larvae reared in tanks were investigated. the larvae (average weight 120.43mg±13.5) were fed 6 times daily starting at the onset of exogenous feeding for 1 week. triplicate groups of fish were offered one of four treatments (1) commercial starter food for rainbow trout، (2) newly hatched artemia nauplii (unenriched) ،(3) highly unsaturated fatty acid (hufa) + vitamin c-enriched artemia nauplii and (4) combination of 10 % hufa+ vitamin c enriched nauplii and commercial starter food. after 1 week, all groups of fish were switched to the commercial diet for an additional period of 3 weeks. statistical analysis of growth after the first week and at the end of the experiment, showed that growth of larvae in various treatments was significantly different (p<0.05). after 4 weeks, the larvae in treatment 3 with the average weight of 657.50 ± 57.93 mg had the highest body weight (p<0.05). the highest percentage of survival (96%) was observed in treatment 3 (p<0.05). proximate compositions of trout larvae after one week feeding with experimental diets showed that the protein in the larvae of treatments 3 and 4 was significantly different compared to other treatments (p<0.05). the best result of resistance to temperature (up to 24ºc) was observed in larvae reared on treatment 3 with 91.34 ± 1.52 percent (p<0.05)