No description available.

Thesis (M. Sc.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 81-87).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 89-92). Also available via the Internet.

Larval development of Penaeus monodon from protozoea (PZ1) to postlarval stages is described on natural and commercially available artificial larval diets under controlled laboratory feed trials. Five species of live microalgae (Tetraselmis chuii, Chaetoceros calcitrans, Skeletonema costatum, Rhodomonas baltica and Pavlova lutheri) were evaluated in feed trials at seven (5-60 cells gl1) cell concentrations with protozoeal larval stages. Performance of five animal diets (rotifers, Mytilus eggs, Artemia nauplii, barnacle nauplii and crab eggs) were examined in feed trials from Mysis (Ml) to postlarvae (PL1). Best results for protozoeal stages were obtained on a combination diet T. chuii + R. baltica at 40 cells µl-', while results from mysis to postlarvae were best achieved on Artemia nauplii. Natural feeds are expensive, difficult to maintain in mass culture and often vary in nutritional value. Larval performance on ten leading brands of artificial larval diet marketed using different process technologies were evaluated in replicated feed trials, together with factors causing variability in larval growth and survival of P. monodon. It was found that nutrient leach loss from unstable artificial feeds in culture conditions increases levels of ammonia and nitrite beyond safe limits. Live microalgal species at 1000 cells µl1 added to culture water reduces these toxic levels. The role of microalgae in larval culture is also examined. To further improve larval growth and survival on artificial diets, proteins from different sources, lipid, vitamin and mineral levels were incorporated in microencapsulated feeds. As a result improvement in larval development to postlarval stage was achieved with feeds containing 60% soya + mussel protein, 5% lipid and 13.9% vitamin and mineral mix. Algal homogenates supplemented to encapsulated feeds produced larval growth and survival comparable to live feed controls. P. monodon larvae were grown to the juvenile prawn stage solely on Frippak feeds. Larval growth was comparable to growth achieved on live feed controls. This study forms a basis for further investigations into nutritional requirements of penaeid prawns.

No description available.

Stocking, transfer and introductions of hatchery-reared salmonids are commonly used to enhance recreational or commercial fisheries and to preserve or re-establish threatened populations (Cowx, 1994). Whilst a lot of effort has been directed toward understanding the production and stocking methods of hatchery-reared salmonids, relatively little is known about the post-stocking survival and behaviour of these fish (Hickley, 1994). In particular there is little available information concerning the post-stocking dietary habits, dispersion and behaviour of hatchery-reared brown trout; particularly following release into standing waters. Consequently, a study was instigated to examine the relative post-stocking dispersion and temporal changes in the diets of hatchery-reared brown trout released to support a commercial recreational fishery, Carron Valley Reservoir. Further laboratory studies examined if resident brown trout display a prior-resident competitive advantage over stocked conspecifics, if hatchery-reared brown trout display non-cost effective aggressive behaviour and the short-term changes in the feeding efficiency of naive hatchery-reared brown trout when experiencing novel prey. 1000 commercially produced hatchery-reared brown trout were marked with a subcutaneous alcian blue tattoo and released into Carron Valley Reservoir at the start of the 1999 fishing season. Stomach samples were taken from angler recaptured hatchery-reared fish along with consecutively captured resident brown trout. The diets of the two groups were compared to assess the relative post-stocking temporal changes in the diets of the hatchery-reared brown trout. This study found hatchery-reared brown trout to consume lower weights and numbers of prey, and they appeared to exhibit a preconditioned 'look up' dietary response to surface prey immediately following release than resident conspecifics. It was further observed that although hatchery-reared brown trout did not immediately adapt to natural diets, their relative foraging efficiency increased over the sample period. In laboratory experiments naive hatchery-reared brown trout further demonstrated the improved feeding efficiency with experience. 1000 commercially produced hatchery-reared brown trout were tagged with a combination of Visible Implant (VI) and 'Floy' style tags prior to release during the 1998,1999 and 2000 fishing seasons. An angler survey programme was instigated to record the reported recapture positions of these tagged fish in order to assess the post-stocking gross dispersion patterns of hatchery-reared brown trout in Carron Valley Reservoir. A further 3 trout were radiotagged to elucidate the fine scale post-stocking dispersion of these fish. This study found hatchery-reared brown trout to disperse quickly from their respective release sites, although over a relatively restricted area. Individual hatchery-reared brown trout were observed to exhibit high levels of activity immediately following release, during which period they covered relatively large total distances within a relatively restricted area. In an artificial stream environment, established wild brown trout displayed a prior-resident competitive advantage over later introductions of both hatchery-reared and wild conspecifics. Established wild fish initiated more aggressive acts and maintained home stations closer to a point source of feed than introduced trout. Introduced hatchery-reared brown trout were more aggressive and exhibited a lower mean specific growth rate than simultaneously stocked wild conspecifics, suggesting that excessive expenditure of energy for unnecessary aggression may contribute to the poor post-stocking survival in hatchery-reared brown trout.

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

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains viii, 110 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 70-71).

Thesis (M.S.) in Marine Bio-Resources--University of Maine, 2006. / Includes vita. Includes bibliographical references (leaves 73-81).

No description available.