Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 97-100).

Thesis (M.S.)--West Virginia University, 2000. / Includes abstract. Includes bibliographical references (p. 78-80).

Thesis (M.S.)--Humboldt State University, 2009. / Includes bibliographical references (leaves 69-72). Also available via Humboldt Digital Scholar.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains vii, 99 p. : ill. Includes abstract. Includes bibliographical references (p. 78-80).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1972. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

The aim of this work was to investigate techniques for controlling the movement of free-ranging rainbow trout. In the first part of the study groups of 50 rainbow trout were successfully conditioned to aggregate at a loudspeaker and feeding point in a 3.5m x 3.5m x 3.5m enclosure in response to a pulsed 140-Hz sound signal played for 10s prior to and during feeding. The development of the response was quantified using three techniques and a study of the factors involved in conditioning showed that, (1) the number of trials was the important criteria in establishing the conditioned response, (2) other fish and the visual cues associated with the experimental environment, as well as the sound signal, were used to mediate the conditioned response and (3) an increase in the size of the conditioning enclosure adversely affected the rate of conditioning. Additional experiments showed that the sound signal amplitude was positively correlated with the number and activity of fish attracted to feed and that conditioned fish "generalized" to frequencies of between 50 and 380Hz. Anaesthesia and handling, and 24 days without training, did not adversely 'affect the conditioned response. In the second part of the study naive fish and fish pre-conditioned to a sound signal were released into an 8-acre loch in two separate experiments. These experiments examined the movements of rainbow trout in relation to an artificial feeding station and showed that fish were attracted to and remained close to the feeding station even in the absence of a sound signal. Preconditioned fish were not attracted to feed using sound although the experimental conditions prevailing at the time of this experiment could have adversely affected the results. A food delivery was, however, a very successful altractant and the possibility of feeding sounds being used in this attraction was investigated, but rejected. The role of other possible cues are discussed. Further experiments quantified the dial changes in the number of fish and the size of the area covered by the group of fish at the feeding station and showed that ration size controlled the numbers aggregating there. The diet and return of stocked rainbow trout were analysed and compared with previous studies. An additional study carried out in an 185acre loch showed that a rainbow trout cage farm had a significant effect on the distribution of rainbow trout within the loch because the cages acted (unintentionally) as supplementary feeding points. Their behaviour is discussed in relation to the results from the previous experiments. Some observations on the swimming behaviour of rainbow ttout in sea cages are also discussed.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains vii, 129 p. : ill., map. Includes abstract. Includes bibliographical references (p. 94-96).

Ph.D. (Zoology) / The contribution of genetics in animal husbandry and agriculture has long been recognised. The application of genetics in fish culture has not yet become established because both overseas and locally the focus was until recently still on culture techniques. In South Africa the only genetic data on the rainbow trout (Parasalmo mykiss) stock is limited to one electrophoretic survey (Op't Hoff et al. 1982). During 1982 to 1985 a survey was done of trout angling management in provincial trout angling waters by the Transvaal Division of Nature Conservation. The goal was to find and eliminate inhibiting factors affecting trout angling in order to provide a better service. Angling results were improved and management of trout waters brought into line with its own potential. The percentage returns of trout caught however, seemed to reach a level that could only be breached by genetically improving the trout strains used for stocking. The inherent inability of inbred domesticated P. mykiss strains to grow and survive in nature has been shown to affect its survival when stocked in streams and dams for angling purposes (Kincaid 1981; Ersbak & Haase 1983).

Before 1980, Ashurst Lake had an exceptionally productive rainbow trout fishery. More recently, Ashurst has become turbid and trout growth rates have declined substantially. The growth, condition, and food habits of a single cohort of rainbow trout was followed from May 1985 until October of 1986. The first year, trout in Ashurst grew from 66 mm to 164 mm in 5 months. Growth reached an average of 24 mm/month from June to September, a time when trout fed primarily on Daphnia. By July of the second year, growth had stopped and condition declined substantially in conjunction with a change in their diet from Daphnia to crayfish and minnows. The decrease in growth rate was attributed to a decrease in the food base coupled with hampered foraging abilities of rainbow trout in water with high turbidity. High tubidity may have resulted from erosion of the surrounding watersheds.

Thesis (M.S.)--University of Wisconsin--Stevens Point, 2006. / Includes bibliographical references (leaves 28-38).