Enrichment of Artemia (Leach) Nauplii with Canola Oil: Effect on Heros severus (Heckel) Larvae Performance and Environmental Stress
Abstract: The effect of canola oil enriched Artemia (Leach) nauplii on growth, survival, resistance to environmental stresses of temperature and oxygen deficiency and fatty acid composition in severum fish, Heros severus (Heckel), larvae were investigated. The larvae (average weight 3 mg ± 0.83) were fed 4 times daily starting at the onset of exogenous feeding for 18 days. Triplicate groups of fish were offered one of two treatments: 1) newly hatched Artemia (Leach) nauplii (unenriched) and 2) canola oil enriched Artemia (Leach) nauplii. Then all groups of fish were switched to the commercial diet for an additional period of 18 days. Statistical analysis of growth after 18 days and at the end of the experiment (36 days), showed that the highest specific growth rates (9.65% ± 0.3), (17.44% ± 0.31) the average weight (17 mg ± 0.95), (65.2 mg ± 0.53) were observed in treatment 2 respectively, but there was no significant difference in survival rate between treatments. The best result of resistance to oxygen deficiency (5 min) was observed in larvae reared on treatment 2 with 75.67% ± 0.66 after 36 days. Result of temperature stress showed no significant difference between treatments. The larvae were also found to convert n-3 fatty acids to EPA and DHA.
Keywords: Canola Oil, Heros severus, Growth, Survival, EPA, DHA