Stress and immunological evaluations of sea urchin treated with four different nutraceuticals

Tazin Fahmi, Purdue University

Abstract

Sea urchins have been considered as delicacy for many years in different regions of the world. Recently, their importance is increasing in the research labs for not only to produce quality gonads for delicacy but to produce pharmaceuticals from them. As they are gaining importance, many people are trying to grow them in aquaculture but due to inadequate knowledge of farming of sea urchins, quality production has not yet been achieved. Some factors such as handling, salinity, and crowding cause stress to sea urchin during aquaculture and stress makes animal susceptible to diseases and also leads to low yield and low quality products. The sea urchin product quality is being determined by the color, texture, freshness and taste of their gonads. Since stress is causing loss to the aquaculture, it is important to identify the cause of stress, determine the stress responses and find possible solution to minimize stress. To investigate the stress responses in sea urchins, physiological and immunological responses against handling were studied in Arbacia punctulata, a purple sea urchin reared in recirculatory system in the lab. For this study, sea urchins were obtained and acclimated for two weeks in optimal conditions. The experiments, then, were conducted for five weeks and the animals were sampled at the end of five weeks. Sea urchins were reared in aquaculture system in different groups - stressed and unstressed, treated with four different feed [control feed (salmon feed) and hydrogenated coconut oil (HCO)-supplemented salmon feed, sunflower oil (SO) -supplemented salmon feed and linseed oil (LO)-supplemented salmon feed]. For this study, sea urchins were obtained and acclimated for two weeks in optimal conditions. The experiments, then, were conducted for five weeks and the animals were sampled at the end of five weeks. Condition factors, gonado-somatic index, packed cell volume, coelomic fluid protein, total and differential cell counts, coelomocyte phagocytic capacity, and respiratory burst activity were observed to measure the stress and immune responses. The results from these experiments showed that handling induces significant physiological and immunological stress responses. Stressed groups showed higher packed cell volume, higher gonado-somatic indices, higher number of total and differential cell counts, lower phagocytic and respiratory bust activities compared to the unstressed sea urchins. Sea urchin groups treated with specific nutraceuticals showed significant variations in their stress responses. In this study, nutraceutical treated groups had lower stress responses than the control feed groups, and among the nutraceutical treated group linseed oil (LO) treated groups had better effects in minimizing stress among all the groups.

Degree

M.S.

Advisors

Mustafa, Purdue University.

Subject Area

Biology|Physiology|Aquatic sciences

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