Mitigation of stress and water deterioration with a root extract of Glycine tomentella during simulated transport of orange-spotted grouper (Epinephelus coioides)

Abstract

Live fish transport has been an uprising research subject. A natural extract of Glycine tomentella (GTE) called I Tiao Gung in Chinese, which had antioxidant and anti-inflammatory activities was able to reduce stress responses during live grouper transport. An effective dosage in packing water decreased transport stress of grouper resulted in 100% survival rate at 18 juvenile grouper/L water, while without GTE the maximal stocking density achieved was 12 juvenile grouper/L. When the stocking density was 16 juvenile grouper/L, or 3 adult grouper/L, addition of 250 mu g/L GTE in packing water resulted in reduced plasma cortisol level, increased SOD activity, reduced lipid peroxides of grouper, and stabilized water quality indicated by increased dissolved oxygen (DO) and reduced total ammonia nitrogen (TAN) measured 4 to 6- h of simulated transport. PO2 levels of grouper stocked in GTE-added packing water and shake as simulated transport (Treatment Group) was significantly (p < .05) higher than that of the Control Group (GTE-free and shake) and Blank Group (GTE-free and no shake) after simulated transport. The present study confirmed that GTE is a potential alternative for the commercial anesthetics, i.e. eugenol and tricaine methane sulfonate (MS222). It is an effective anti-stress agent applicable to the protocol for live food-fish transport.