Projects

Sea urchins are improved candidates for aquaculture and bomedical/ecotoxicological models

End Date: 01/31/07

Abstract

Worldwide sea urchin fisheries are declining and demand is growing. Worldwide markets for sea urchin gonads (roe) have increased dramatically, having a total value of more than $300 million in 2003. With worldwide loss of urchin fisheries, the scientific community now emphasizes the need for fisheries management and aquaculture. As a biomedical model, urchins are an ideal organism for learning how genes and proteins regulate growth and development with potentially profound implications for understanding human biology. Investigators rely on stocks collected from nearshore habitats in which environmental and nutritional history of these urchins are not known and quality of their gametes varies.

The EPA has come under increased criticism for the use of mammalian models in bioassessment of environmental hazards. This criticism occurs in spite of increased pressure to develop protocols to evaluate potential hazardous compounds found or released in the aquatic environment. These protocols should evaluate all life history stages of model organisms, including long-term epigenetic effects. Cultured urchins would provide a predictable, year-round supply of consistent quality for evaluating toxicants. Simple educational models of organism growth and development are essential in secondary schools and colleges. Sea urchins can be easily maintained, and gametes can be recovered for fertilization and embryogenesis, allowing students to directly observe, manipulate, and study these fundamental processes in biology.

The major impediment to sea urchin culture is the total lack of nutritionally complete, commercially available diets having the required physical characteristics. Thus, the objective is to determine dietary nutritional requirements of urchins with the concomitant development of practical, semi-purified and purified diets for research and aquaculture for two Gulf of Mexico urchin species, Tripneustes ventricosus and Lytechinus variegatus.

Semi-purified and purified feeds will be used to determine dietary nutrient requirements for macronutrients (e.g. protein, energy) and micronutrients (e.g. carotenoids, selenium, iron, vitamins). We propose to evaluate:

  1. juvenile seedstock production and
  2. roe production in adults.

We need to further identify those nutrients that promote maximal growth and survivorship in juveniles. We also need to identify those nutrients that promote gamete production in the gonads (for biomedical and environmental assessment stock) and those that reduce gamete production (for aquaculture). We need to further refine our newly developed pelleting process that is commercially feasible at this time.

Within a two-year period we will have developed diets that promote gonad production ideal for medical, ecotoxicological and educational uses in terms of a predictable supply of quality gametes, zygotes, larvae, juveniles and sub-adult sea urchins. These diets should also produce commercially desirable roe with maximum somatic growth (i.e. phagocytic nutritive cell) and desired quality in terms of color, size, texture, and taste. With multipliers, production and marketing of commercial sea urchin feeds for aquaculture and research feeds for biomedical and ecotoxicological studies can be a multimillion dollar industry in the U.S. We have received commitments from several industry partners including Dipasa USA, Inc., Bentoli Inc., and Zeigler Bros. Inc. We have received widespread support and plan to establish an NIH National Resource Center for Sea Urchins to support biomedical and ecotoxicological research efforts.

Objectives

The major impediment to sea urchin culture is the total lack of high quality, nutritionallycomplete, commercially-available dry pelleted diets having the required physical characteristics. The primary object of this ongoing study is to determine dietary nutritional requirements of sea urchins with the concomitant development of practical semi-purified and purified feeds that can be used for research and commercial aquaculture for several urchin species. We are evaluating the aquaculture potential of the sea urchin, Tripneustes ventricosus and Lytechinus variegatus, in the Gulf of Mexico region.

Methodology

Semi-purified feeds will be further developed and used to determine dietary nutrient requirements for macronutrients (e.g. protein) and micronutrients (e.g. vitamins) respectively. We propose to evaluate two primary life history stages, (1) juvenile seedstock production and (2) roe production in adults. We need to further identify those nutrients that promote maximum growth, survivorship, and normal physiological function in developing juveniles. Technologies for juvenile production can be used both in aquaculture and in development of stocks for biological models. We also need to identify those nutrients that promote gamete production in the gonad of adults (for biomedical and environmental assessment stock) and those that reduce gamete production in the gonad (for aquaculture, where gamete production is not desired, but storage of nutrients in the gonad is preferred). We need to further refine our newly developed technologies for a pelleting process that is commercially feasible. 

Rationale

Within a two year period we will have developed diets that not only promote gonad production ideal for medical, ecotoxicological and educational uses in terms of a predictable supply of quality gamete zygotes, larvae, juveniles, and sub-adult sea urchins, but also commercially desirable roe with maximum somatic growth (i.e. phagocytic nutritive cell) with desired quality in terms of color, size, texture, and taste. As a result, new commercial industries would include hatcheries, production facilities for grow-out, processing plants, feed manufacturing, transportation, and other satellite industries. With multipliers, production and marketing of commercial sea urchin feeds for aquaculture and research feeds for biomedical and excotoxicological studies can be a multimillion dollar industry in the U.S. We have 
received commitments from several industry partners including Dipasa USA, Inc., Bentoli Inc., and Zeigler Bros. Inc. not only for financial support but also development of commercial products. We have received widespread support for these activities from investigators and it is our plan to establish an NIH National Resource Center for Sea Urchins to support biomedical and ecotoxicological research efforts.