Date Awarded

1995

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Virginia Institute of Marine Science

Abstract

There has been a growing interest in the commercial aquaculture of striped bass, Morone saxatilis. Little is known, however, about the nutritional requirements and feeding physiology of striped bass larvae. The objectives of this study were (a) to evaluate the efficiency of the live food enrichment techniques in studying the nutritional requirements for polyunsaturated fatty acids (PUFA), phospholipids and free amino acids, (b) to determine the ontogenetic changes of lipolytic enzymes, and (c) to develop a microencapsulated diet for striped bass larvae as full or partial replacement of live food. Three enrichment techniques, namely, microencapsulated fish oil, yeast/fish oil emulsion and unicellular algae, Chlorella sp. were evaluated for their efficiency in improving the n-3 PUFA content of Artemia nauplii to striped bass larvae. The enrichment of the Artemia nauplii appeared to increase the eicosapentaenoic acid content and enhance the growth of the striped bass larvae. The uptake and metabolism of &\sp{14}&C-glycine or &\sp{14}&C-phosphatidylcholine labeled liposomes by freshly hatched Artemia nauplii were investigated as a new technique for amino acid and phospholipid. The results of this study suggest that liposomes may be used to enrich Artemia nauplii with phospholipids and free amino acids. Ontogenetic changes of triacylglycerol hydrolase, wax ester hydrolase and phospholipase A&\sb2& were determined in the fertilized eggs and premetamorphosed larvae of striped bass and the larval food Artemia using radioassays. It was estimated that first feeding striped bass larvae had the capacity to digest 47% of their daily lipid ingestion. A complex protein-walled microcapsule (CWC) was prepared by incorporating lipid-wall capsules containing highly water soluble nutrients along with other dietary materials in a cross-linked protein-wall microcapsule. In vitro experiments indicated that the CWC was digested by the crude enzyme extract from striped bass larvae or purified porcine pepsin and trypsin. Diet acceptability, growth and survival of striped bass larvae fed complex protein-walled microcapsules were investigated in two separate experiments. In both experiments, the acceptability of microencapsulated diets was high. Neither microencapsulated diet support growth when solely fed to the larvae. The results of this study suggested that CWC can be used for partial replacement (60%) of live food without any significant effect on growth and survival of striped bass larvae.

DOI

https://dx.doi.org/doi:10.25773/v5-3dyk-ty09

Rights

© The Author

Download

Share Feedback

Share

COinS