| Summary: | Development of formulated diets for use in abalone culture demands knowledge of
the animal's nutritional requirements, growth, and metabolism. This thesis addresses some
important aspects of these issues with regard to the abalone Haliotis kamtschatkana.
Protein requirement was investigated from the standpoint of how protein utilization is
affected by dietary protein content, amino acid balance, and protein sparing, together with
the possible amelioration of the last through enzymatic adaptation to diet. Focus on
protein utilization stems from the fact that protein is a costly dietary ingredient and is an
essential nutrient for protein growth. With respect to abalone growth, I assessed the
efficacy of administering vertebrate growth hormones which enhance growth in other
cultured aquatic animals. I also investigated metabolism of cells isolated from the abalone
digestive gland (a primary site of metabolic conversions) from the standpoints of seasonal
variation in metabolic activity, and relationships between digestive gland and gonad
activity during the reproductive cycle.
My data show that optimal utilization of dietary protein in Haliotis kamtschatkana
occurs when diets are formulated with about 20 % dry mass of protein, and with
carbohydrates, rather than fats, comprising the energy source since enzymatic adaptation
to diet does not alter protein-sparing effects. With respect to growth, I found no
enhancement from treatment with recombinant bovine or porcine somatotropin, or
somatostatin (vertebrate growth hormones). Furthermore, I found that metabolism in
these animals is seasonal and possibly inter-related with the competitive needs of
reproduction and somatic growth. These findings contribute to the general understanding
of abalone biology and provide information useful for culture of abalone.
|
|---|
