No description available.

No description available.

The eastern oyster (Crassostrea virginica Gmelin 1791) has great ecological and economic importance but populations have declined, especially in Chesapeake Bay, to historically low numbers. Hatcheries strive to produce oysters with beneficial characteristics for supplementation and commercial purposes, both natural and stimulated mass spawning. Unequal contribution of parents in mass spawnings potentially can lead to high levels of inbreeding and a loss of beneficial characteristics in offspring. In this study, we determined microsatellite genotypes for parents (n^parents =24, 49, and 77 parents) and progeny (n=96 each) of three hatchery-produced families and used the data for parental assignment. We observed the presence of more than two alleles per locus for some offspring, yet because genetic analysis software only allows for a maximum of two alleles per locus, we chose the two alleles with the strongest signals. For the three parent “populations,” 71% of alleles had frequencies of <0.05 and observed heterozygosities were lower than expected by an average factor of 0.27. Inbreeding within the various parent populations was similar across the three families ranging from F^IS 0.26–0.43. In all three families, the offspring exhibited greater levels of genetic diversity and lower inbreeding levels than the parents (F^IS 0.14–0.21), and in some cases offspring exhibited alleles that were not present in the parents. Variance in the number of offspring produced per parent was observed for all families and in general, <10% of potential parents (generally 2-5 females and 1-3 males) produced >10% of the offspring. Reproductive success for spawning parents, N^b, determined by three methods, ranged from 0.07 to 0.27. As the number of parents per family increased, a higher proportion of parents failed to produce offspring. Across all three families, the average effective number of breeders was N^b = 7.1 and the level of reproductive success was inversely proportional to the number of potential parents. This finding implies that to maintain high levels of diversity and beneficial characteristics in the offspring (and to avoid the chance of unintentional inbreeding), hatcheries should perform more spawnings with fewer parents.

Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-22Bitstream added on 2014-06-13T18:08:09Z : No. of bitstreams: 1 pavanelli_cam_me_jabo.pdf: 994445 bytes, checksum: 1f78bc06337409e7583f2f9c3ed06cb2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Avaliou-se o efeito da temperatura da água no cultivo de larvas de Macrobrachium amazonicum. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos (temperaturas) e quatro repetições. Foram realizados dois experimentos. No primeiro, a temperatura foi avaliada em um amplo espectro (20, 25, 30 e 35°C). No segundo, os tratamentos testados foram 26, 28, 30 e 32°C, definidos de acordo com os melhores resultados obtidos no experimento 1. Cada experimento foi desenvolvido em 16 tanques de larvicultura de 63 L contendo água na salinidade 12 e providos de filtro biológico, aeração e aquecimento controlado por termostatos digitais. A densidade de estocagem foi de 100 e 85 larvas/L nos experimentos 1 e 2, respectivamente. O desenvolvimento larval foi mais lento no cultivo em 20°C, seguido pelos cultivos em 25 e 26°C. Nessas temperaturas, a metamorfose não ocorreu ou foi inexpressiva no tempo de cultivo adotado (17 dias). A temperatura de 35°C apresentou mortalidade total das larvas no 13º dia de cultivo. Conclui-se que a larvicultura de M. amazonicum pode ser realizada em temperaturas que variam de 25 a 32°C. Porém, o cultivo em 30°C apresentou os melhores resultados, maximizando a produção de pós-larvas e minimizando o tempo de cultivo / We evaluated the effect of water temperature in the culture of larvae of Macrobrachium amazonicum. The experimental design was completely randomized with four treatments (temperatures) and four replications. Two experiments were conducted. At first, the temperature was evaluated in a broad spectrum (20, 25, 30 and 35°C). In the second, the treatments were 26, 28, 30 and 32°C, defined in accordance with best results obtained in Experiment 1. Each experiment was carried out in 16 hatchery tanks containing 63 L of water salinity at 12 and with a biological filter, aeration and heating controlled by digital thermostats. Stocking density was 100 and 85 larvae/L in experiments 1 and 2, respectively. Larval development was slower in culture at 20°C, followed by cultivation at 25 and 26 ° C. At these temperatures, the transformation did not occur or was negligible in the time of culture adopted (17 days). The temperature of 35°C showed a total mortality of larvae on day 13 of culture. It is concluded that the hatchery M. amazonicum can be performed at temperatures ranging from 25 to 32°C. However, culture at 30°C showed the best results, maximizing the production of post-larvae and minimizing the time of culture

The results of a two-year research project designed to develop techniques for closed cycle production of bigeye scad (Selar crumenophthalmus) are described. Broodstock fish were captured approximately 5 nautical miles east-southeast of Key Biscayne Florida in waters 100 to 400 feet deep. A 28-ton, eight tank, recirculating aquaculture system (RAS) was designed, built and used for broodstock maturation and growout. Between June and October of 2009, thirty-six volitional spawning events were recorded during a five-month spawning season. A larval rearing protocol focused on modified greenwater techniques using microalgae (Isochrysis galbana and Nannochlopsis oculata) at total concentrations of 400,000 cells ml-1 and rotifers (Brachionus plicatilis) at densities of 30 to 50 rotifers ml-1 was developed. A larval rearing trial using this protocol produced 1,940 fully weaned, 45 dph fingerling bigeye scad with an average length of 38.8 ml and average weight of 1.3 g. Growout trials conducted from 45 dph to four and a half months post hatch were conducted. During growout trials fish were fed ad libitum twice a day using commercially available feed with 44% crude protein and 18% crude fat. Growout trials resulted in an average survival rate of 88%, absolute growth rates (AGR) of 28.23 to 30.26 g, and feed conversion ratios (FCRs) between 1.17 and 1.38. Results from an informal survey of local recreational fishing interests indicate that there is a large potential live-bait market for bigeye scad. Overall results from these trials show that bigeye scad aquaculture is technically feasible and suggests that the species is strong candidate for commercialization.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 98-111).

Thesis (M.S.)--Humboldt State University, 2007. / Includes bibliographical references (leaves 76-81). Also available via Humboldt Digital Scholar.

Thesis (Ph.D.) -- McMaster University, 1998. / Includes bibliographical references. Also available via World Wide Web.

Thesis (M.S. in zoology)--Washington State University, August 2008. / Includes bibliographical references (p. 41-44).

Oregon’s fish hatchery system developed in the late 1800’s in response to salmon fishery losses. Salmon hatcheries consist of a number of built components. ‘Growing fish’ requires a variety of building types which support the hatchery process as well as constant input of resources. In addition to surveying and inventorying fish hatchery resources, this study will analyze the social, economic, cultural, and environmental conditions under which these fish hatcheries were organized and commissioned. Ultimately, this survey will not only serve as a baseline for future, more intensive-level surveys, but will also provide a foundation for a National Register Multiple Property Submission. The use of hatcheries to sustain native Oregon fish species constitutes a major aspect of Oregon’s fishing and environmental conservation efforts. Oregon’s heritage hatcheries stand as physical reminders of early conservation activity and while their preservation provides a more complete picture of Oregon’s relationship with natural resources