Effect of supplemental l-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 supplemental l-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