Fairy shrimp is an anostraca plankton which is raised for watching and scientific study. In recent year, due to the large requirement of fairy shrimp in the market, to increase the hatching rate of fairy shrimp is an important topic. It is found that when an Artemia Cysts hatched by light, the pigment absorption spectra in the Cysts match with the optical wavelength of the experimental incubators. Furthermore, the effect of ultrasound can stimulate the growth or activation of the fairy shrimp, when the ultrasonic parameters of frequency, intensity, exposure time and exposure period are properly controlled in the hatching experiments. This thesis is then focusing on the biological activities to increase the hatching rate of fairy shrimp by light and ultrasound exposure. This work investigates the light effect on the hatching experiment using different wavelength and intensity of LED light; in addition, Cysts is exposed to ultrasound by ultrasonic cleaner and transducer. The resonant frequency of the Cysts is obtained from Rayleig ¡VPlesset bubble activation formula. The radiation of the resonant and non-resonant regions during the hatching experiments are then set up by this resonant frequency for comparison. Finally, according to the experimental results, the correlations of hatching rate with light wavelength, light intensity, resonant frequency and ultrasound intensity are studied by Taguchi Method to understand the play role of the light and ultrasound. The research results show that the hatching rate is 25 % by lamp irradiation, and the maximum hatching rate is 42.5 % by blue light in the light experiment. In ultrasound experiment, the highest incubate percentage, 35 %, is obtained by ultrasound frequency 0.25 MHz and ultrasound intensity 39.2 mW/cm2. In the confirmed test, the blue light plus ultrasound frequency of 0.25 MHz plus ultrasound intensity of 30.9 mW/cm2 can let the incubate percentage up to 48.3%. This is the highest incubate percentage one can get from these experiments. Finally, the results of Taguchi analysis shows that the Confidence level of light affecting the hatching rate is 100%; thus, light source is the most critical factor to affect the hatching procedure. The results of this research can be referred by an endangered species or high economic value of species to increase the rate of hitching.

This dissertation provides a thorough analysis of the costs associated with, and efficacy of, sequential license buyback auctions. I use data from the Texas Shrimp License Buyback Program - a sequential license buyback auction - to estimate the effects of a repeated game set-up on bidding behavior. I develop a dynamic econometric model to estimate parameters of the fisherman's optimal bidding function in this auction. The model incorporates the learning that occurs when an agent is able to submit bids for the same asset in multiple rounds and is capable of distinguishing between the fisherman's underlying valuation of the license and the speculative premium induced by the sequential auction. I show that bidders in the sequential auction do in fact inflate bids above their true license valuation in response to the sequential auction format. The results from our econometric model are used to simulate a hypothetical buyback program for capacity reduction in the offshore shrimp fishery in the Gulf of Mexico using two competing auction formats: the sequential auction and the one-time auction. I use this simulation analysis to compare the cost and effectiveness of sequential license buyback program relative to one-time license buyback programs. I find that one-time auctions, although they impose a greater up-front cost on the management agency - are capable of retiring more fishing effort per dollar spent then sequential license buyback programs. In particular, I find one-time license buyback auctions to be more cost effective than sequential ones because they remove the possibility for fishermen to learn about the agency's willingness to pay function and use this information to extract sale prices in excess of the true license value.

No description available.

Thesis (M.Sc.), Memorial University of Newfoundland, 2000. / Bibliography: leaves 98-111.

Thesis (M.S.)--Mississippi State University. Department of Food Science, Nutrition and Health Promotion. / Title from title screen. Includes bibliographical references.

Sex-specific nutritional requirements for crude protein and fat were demonstrated in cultured (F1) Penaeus stylirostris brood stock. Female shrimp required diets which had higher protein (32 versus 27%), lower fat (2.5 versus 3.9%), higher protein/calorie ratios (8.5 versus 6.8% protein/kcal/g), and much higher protein/fat ratios (15.4 versus 7.8% protein/% fat) than males. These studies have also demonstrated a nutritional demand corresponding to the onset of ovarian maturation, a phenomenon which was explained as a reduction in growth rates at the attainment of 30 to 35 g in shrimp fed deficient diets. Both the quality and the quantity of dietary fat were shown to affect the growth of P. stylirostris brood stock. Male growth was positively correlated with the quantity of eicosapentaenoic acid (20:5 ω3) in the diets. The females were not affected by the types of fatty acids in the fat; they were influenced more by the quantity of fat, i.e., as the fat level of the diet increased, the growth decreased. Cold extrusion feed (CEF) diets supplemented with squid, and diets which included squid as one of the ingredients in the formulation, were found to stimulate better growth in both male and female brood stock as compared to CEF diets of equal protein and fat content without squid. The protein/fat ratio, as well as the content of polyunsaturated fatty acids (PUFA), were suggested to be responsible for the improved growth. Comparisons were made between the quality of spawns from wild P. stylirostris matured in captivity (P1) and F1 shrimp. Protein levels of the eggs did not correlate with either the number of eggs spawned or the eclosion rate. The number of the eggs spawned was correlated positively with the levels of eicosaenoic acid (20:1 ω9) in both P1 and F1 eggs, and correlated negatively with linoleic acid (18:2 ω6) in P1 eggs only. Spawning times were reported to occur later in the evening as summer approached. A significant, negative correlation was observed between the elapsed time from copulation, i.e., collection of fertilized shrimp, to spawning and eclosion rate. Also, a significant positive correlation was observed between the number of spawns which contained eggs which did not hatch, and the elapsed time from copulation to spawning. The number of eggs spawned and the eclosion rate were found to be higher in P1 shrimp as compared to F1 shrimp. Also, first breeding season spawners (FBS) had better quality spawns than second breeding season (SBS) spawners, i.e., more eggs with higher eclosion rates. A general reduction in the quality of the spawns was therefore implicated as a result of the culture conditions. Multiple spawning behavior was observed and there appeared to be no qualitative or quantitative difference between spawns. Tank size and shape were demonstrated to affect the onset of ovarian development and the transfer of the spermatophore. A minimum of three meters was thought to be required for the development of the ovaries and the successful transfer of the spermatophore.

The development of shrimp aquaculture in the Mekong Delta of Viet Nam is implicated in several patterns of local and regional change. These change trajectories are the emergent properties of complex processes embedded in particular social and spatial contexts. While places have become more interconnected through the global shrimp trade, those interconnections have been highly uneven, distributing risks and rewards disproportionately and producing new forms of conflict and cooperation among participants in the production network.Land use and farming systems in the coastal delta have changed profoundly in recent years. While some areas have become effectively `locked in' to shrimp farming due to environmental changes initiated by salt-water aquaculture, others have remained more flexible, able to rotate rice and shrimp seasonally. Hydrologic conditions, water infrastructures, and farmer experience all contribute to the path-dependence of these change trajectories, but commodity prices exhibit the strongest influence on their direction. Price stabilization may contribute to making prices a sustaining, `slow' variable in system change, not a disruptive `fast' one, heightening overall resilience.The production network of Mekong Delta shrimp is articulated through a variety of socially embedded relationships. Most producers are linked with international markets through informal ties with input suppliers based on trust and shrimp buyers, a relationship marked by opportunism. Processors operate through long-term informal relations with importers based on quality and consistency. This variegated network of relationships means farmers bear the brunt of price shocks, but processors lack quality assurance and traceability. Efforts to link chain participants into closer affiliation must pay attention to these relationships' effects on commodity chain governance.The globalization of the shrimp industry brought about conflicts between producers in the Mekong and Mississippi Deltas. Feminist geographers have posited several responses to globalization, from `counter-topographies' to `diverse economies/resubjectivization.' Living in Viet Nam and working with shrimp producers, I attempted to use these approaches to articulate an internationalist and trans-regional politics. Interactions with people there primarily resubjectivized me and reinforced national-scaled spatial imaginaries, however. Nevertheless, being `Uncle America' offered an insightful perspective into how some Vietnamese understood themselves and Viet Nam's tortured relationship with the U.S.

Clinical signs and lesions of Taura syndrome virus (TSV) infection in Penaeus monodon were investigated by histological and in situ hybridization (ISH) analyses. Mortality among P. monodon inoculated with 2 genotypic variants of TSV (Th04Pm and Th04Lv) appeared on Day 3, with 2 out of 10 shrimp dying. Severe necrosis of cuticular epithelial cells and lymphoid organ spheroids, indicative of acute and chronic phase lesions of TSV infection, respectively, were detected in the samples. Both Th04Pm and Th04Lv belonged to a phylogenetic family of Asian TSV isolates. The results demonstrate that both mortality and histological lesions are associated with TSV infection in P. monodon.Infection with 4 genotypic variants of TSV (Bz01, Th04, UsHi94, and Ve05) in TSV-resistant (TSR) and TSV-susceptible (Kona) Litopenaeus vannamei was investigated. Survival probabilities of TSR shrimp were higher than those for Kona shrimp with all 4 variants. Th04, UsHi94, and Ve05 gave no Taura syndrome lesions with TSR shrimp. In contrast, TSR shrimp challenged with Bz01 and Kona shrimp with all 4 TSV variants exhibited severe necrosis of cuticular epithelial cells and lymphoid organ spheroids. Real-time reverse transcription polymerase chain reaction (RT-PCR) revealed that mean TSV copy numbers in TSR shrimp infected with Bz01, Th04, and UsHi94 were significantly (p < 0.0005) lower than those in Kona shrimp. In contrast, mean TSV copy numbers in TSR and Kona shrimp infected with Ve05 were not significantly different (p > 0.4). The results show that TSR L. vannamei are susceptible to infection but give high survival rates following challenge by all 4 variants of TSV.To identify the viral replication site within shrimp infected cells, the viral RNA was located in association with virus-induced membrane rearrangement by electron microscopic ISH. Ultrastructure in the infected cells, analyzed by transmission electron microscopy, included the induction and proliferation of intracellular vesicle-like membranes, while the intracytoplasmic inclusion bodies and pyknotic nuclei were frequently seen. TSV RNA and TSV particles were found to be associated with the membranous structures. The results suggest that the proliferating membranes carry the RNA replication complex and that they are the site of nascent viral RNA synthesis.

This thesis examined the economics of producing high value bio-ingredients such as chitin and carotenoprotein from shrimp processing waste in Newfoundland. The shrimp waste in the province was estimated to be at least 37000 tons annually. A survey of shrimp processing plants in the province revealed that the waste generated was relatively pure with little or no foreign material. The economic engineering approach was employed to estimate the production cost of chitin and carotenoprotein at the laboratory and pilot scale levels. At the laboratory scale where 480 kg/year of raw material (shrimp waste) was processed, the cost of chitin and carotenoprotein was found to be $159/kg and $315/kg, respectively. At the pilot scale level, the cost of chitin and carotenoprotem was estimated to be $125/kg and $244/kg, respectively based on volume of 4800 kg/year. Sensitivity analysis was carried out to establish the cost variations due to changes in the quantity of starting raw material, labor cost and cost of laboratory supplies (chemicals and enzymes). The cost of chitin and caroteinoprotein showed a decreasing trend with increasing scale of production. An expert opinion survey was conducted with a selected panel of 9 experts from the shrimp processing industry, chitin related industry, and the academic/research community to determine the potential market of the high-grade chitin/chitosan in Canada. The results showed that the health and nutraceutical industry is the most promising niche for high-grade chit in/chitosan. The survey also indicated that potential market would be high in Ontario and Quebec due to the presence of large health and nutraceutical companies in the big metropolitan areas of these regions.

This thesis investigates small-scale community-based shrimp aquaculture (CBSA) in northwestern Sri Lanka. The objectives are to explore: (1) community-based shrimp aquaculture; (2) commons institutions and application of commons rules; and (3) policy implications (i.e., as an alternative to large-scale operations in ensuring sustainability). Data were gathered from three communities in northwestern Sri Lanka, through participant observations; semi-structured interviews; focus group discussions; and key informant interviews. Presence of small-scale community-based institutions is evident. Arguably, commons in this context are social-ecological systems, including the interconnected natural water body. Main characteristics of the existing resource governance system are multi-level commons institutional structure; zonal crop calendar system; collaborative/participatory management approach; and better management practices. A SWOT (strengths, weaknesses, opportunities, threats) analysis proves the viability of existing CBSA. This thesis recognizes CBSA as an alternative approach to large-scale aquaculture operations to ensure sustainability in the long run.