| dc.contributor.author | Kean-Howie, Joan Cavell. | en_US |
| dc.date.accessioned | 2014-10-21T12:35:55Z | |
| dc.date.available | 1994 | |
| dc.date.issued | 1994 | en_US |
| dc.identifier.other | AAINN98877 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55445 | |
| dc.description | !The expanding molluscan culture industry and the concomitant increasing reliance on hatchery produced spat have created a demand for detailed fundamental knowledge on the nutritional requirements of bivalve molluscs. Our knowledge in this field has lagged behind that of fish and crustacean nutrition simply because it is more difficult to do. Involved is the production of synthetic diets of defined nutrient composition and the development of protocols for testing and evaluating these diets. | en_US |
| dc.description | This thesis has focused on a sodium alginate microparticulate diet which was tested in nutrition studies on larval and juvenile bivalve molluscs. New methods of diet presentation, quantifying ingestion and measuring digestibility were used. The microparticulate diet was ingested and assimilated by juvenile sea scallops (Placopecten magellanicus) and bay scallops (Argopecten irradians). However, growth and survival were greater among scallops fed algae. In contrast, short term tests with bivalve larvae and spat (Crassostrea gigas and Tapes philippinarum) show that the microparticulate diets support growth and survival at least as well as the algae diets. | en_US |
| dc.description | The effect of current velocity and food concentration on the ingestion rates of young sea scallops was tested in a flow tank using a factorial design with fifteen treatment combinations to evaluate ingestion at three current velocities (5, 10, and 15 cm sec$\sp{-1}$) and five food concentrations (5, 10, 20, 40, and 80 mg l$\sp{-1}$) of the microparticulate diet, labeled with Fluoresbrite$\sp{\rm TM}$ beads. Digestive tracts were excised, homogenized and the number of beads enumerated to quantify ingestion. Ingestion of the microparticulate diet was greatest when fed at 20 mg 1$\sp{-1}$ 10 cm sec$\sp{-1}$. This direct method for quantifying ingestion is more accurate than indirect methods, and it can be also be used to investigate other variables which impact on feeding. Based on this work recirculating units were designed for long term nutrition experiments with juvenile scallops, which kept 2l of seawater in motion at a flow rate of 8-9 cm. sec$\sp{-1}$, and the ration of microparticulate diet in suspension. These recirculating units were also successfully designed to be inexpensive, and easily serviced and maintained. | en_US |
| dc.description | To measure digestion, the sodium alginate diet was labeled with a Procion dye and was subsequently incubated in vitro with digestive enzymes from scallop crystalline styles and diverticula. Dye release was monitored and compared to treatments of pure amylase and protease enzymes. This in vitro digestion method is useful for testing the digestive capabilities of various bivalves prior to the in vivo testing with the microparticles. Microparticles labeled with either the Procion dye or the Fluoresbrite$\sp{\rm TM}$ beads were easily seen (at a low magnification) inside the larvae of three species tested allowing ingestion and digestion of microparticles of microparticles to be confirmed and monitored. | en_US |
| dc.description | In conclusion, the sodium alginate microparticulate diet shows great promise as a tool in nutrition studies with larval and juvenile bivalve molluscs. Equipment and protocols designed and tested in this thesis research will allow researchers to focus on specific nutrient requirement of bivalve molluscs and to develop practical, economical diets. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1994. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Agriculture, Animal Culture and Nutrition. | en_US |
| dc.subject | Agriculture, Fisheries and Aquaculture. | en_US |
| dc.title | The application of sodium alginate microparticulate diets for nutrition research on juvenile and larval bivalve molluscs. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
