Effect of supplementall-ascorbyl-2-polyphosphate in enriched live food on the antioxidant defense system of Penaeus vannamei of different sizes exposed to ammonia-N.

The effects of supplementall-ascorbyl-2-polyphosphate (APP) in enriched live food ( Artemia) on reactive oxygen intermediate (ROI) and free radical scavenging enzyme (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione transferase) activities in the muscle of Penaeus vannamei of two sizes exposed to ambient ammonia-N, were investigated. Significantly, decreased ROI value was found in prawns fed on enriched Artemia compared with those fed on starved Artemia ( P < 0.05); the decrease was 24% and 36%, respectively. In both size classes, the antioxidant enzyme activities in prawns fed on enriched Artemia were higher than in those fed on starved Artemia ( P < 0.05). The results demonstrated that the supplementation of ascorbic acid in enriched live food ( Artemia) enhanced the antioxidant capacity of prawn, increasing its defense system that may fight against environmental stress, leading to impaired ammonia toxicity. [ABSTRACT FROM AUTHOR]