NUTRACEUTICAL-INDUCED STRESS MODULATION IN SEA URCHINS, REARED IN AQUACULTURE

Marine vertebrates and invertebrates are important source of high quality and low fat protein and account for 16% protein demand worldwide. Among the marine animals, sea urchin is the newest organism used as food, medicine and research animal model and is harvested in many part of the world. This study evaluates the stress response, the effects of nutraceuticals on the modulation of stress and immune response and gonadal fatty acid content in sea urchin (Arbacia punctulata) reared in aquaculture. Sea urchins were reared in lab aquaculture system in different groups-stressed and unstressed, treated with four different feed groups (control, hydrogenated coconut oil, sunflower oil, and linseed oil). The test animals were acclimated for two weeks in optimal conditions before the experimental period. Terminal samplings were done at the end of five weeks. Physiological and immunological parameters were measured which included condition factor, gonado-somatic index, packed cell volume, coelomic fluid protein, total differential cell counts, and coelomocyte phagocytosis and respiratory burst activity. Increased phagocytic cell number but decreased phagocytic activities were identified in stressed groups. Increased number of white spherule, red spherule and vibratile cells were also found in stressed groups. Changes in ceolomic fluid protein, respiratory burst activity and gonado-somatic index were identified in different stressed groups. Gonads were preserved in -80^oC for further biochemical analysis.