Theses and Dissertations
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Of special note are theses cited in James R. Meiman's Little South Poudre Watershed and Pingree Park Campus (Colorado State University, College of Forestry and Natural Resources, 1971).
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Browsing Theses and Dissertations by Author "Angeloni, Lisa M., committee member"
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Item Open Access Evaluating dietary and behavioral impacts of commercial-type diets on the growth and anti-predator responses of Snake River cutthroat trout (Oncorhynchus clarkii behnkei)(Colorado State University. Libraries, 2016) Owens, Cheyenne Elizabeth, author; Myrick, Christopher A., advisor; Vieira, Nicole K. M., committee member; Angeloni, Lisa M., committee memberCutthroat trout (Oncorhynchus clarkii) are raised for restoration stocking and to provide boutique sport fishing opportunities. Because of limited cutthroat-specific culture information, cutthroat trout have been raised using diets and techniques developed for rainbow trout (Oncorhynchus mykiss), resulting in inconsistent growth performance. There is also evidence that intensive culturing may diminish anti-predator behavior in salmonids, which has not been tested in cutthroat trout. A brief overview of the state of cutthroat trout is described in chapter one of this thesis. The second chapter of this thesis describes a 6-month feeding trial conducted on juvenile Snake River cutthroat trout (Oncorhynchus clarkii behnkei) fed six different feed formulations. Two floating control diets were chosen for this study (Skretting Classic Trout and Skretting Steelhead), along with three floating commercial-type formulations with varying crude protein (CP) and crude lipid (CL) levels (40 CP:12CL, 45CP:16CL, and 45CP:24CL) and one floating experimental formulation (40CP:16CL diet with lysine, methionine and threonine balanced to match the 45CP:16CL diet – BFTC Experimental). Diet significantly (P<0.05) affected final average fish weight, with fish fed Skretting Steelhead, BFTC Experimental, and 45CP:24CL weighing significantly more than fish fed 40CP:12CL. Proximate composition was also altered by diet, with fish fed 45CP:24CL having significantly higher crude energy levels than fish fed 40CP:12CL and Skretting Classic Trout. In a simple cost analysis, it was found that the BFTC Experimental diet provided the lowest cost per pound of fish out of all diets. The results indicate that diets with greater than 40% protein and 12% lipid provide the greatest growth in juvenile Snake River cutthroat trout, and that amino acid balanced diets provide a cost efficient option for cutthroat trout growers. The third chapter of this thesis describes a study wherein fish from the diet study were divided into one of two different size classes (small [12 ± 2.5 cm TL], and large [20 ± 2.5 cm TL]) and observed during open field testing and during exposure to a novel avian predator model (great blue heron, Ardea herodias). Additional testing was run separately on a medium size class [16 ± 2.5 cm TL]. Small fish were significantly (P<0.05) less likely to freeze during open field tests than large fish and potentially more likely to dart (P=0.0652) than medium fish during simulated predator attacks. Significant differences in freezing response between small and large fish fed different diets were observed (P<0.05), with fish fed 45CP:16CL and BFTC Experimental showing a higher probability of freezing than fish fed Skretting Steelhead. Potential differences in darting response between medium fish fed different diets were also observed (P=0.0825), suggesting that differences in ingredients or ingredient inclusion levels between experimental and control diets had subtle effects on behavior. The results indicate that hatchery-reared cutthroat trout do exhibit anti-predator behaviors in response to a novel predator, however further research is necessary to determine if these behaviors differ from those exhibited by wild cutthroat trout.Item Open Access Survival of Rainbow Trout fry in the wild: a comparison of two whirling disease resistant strains(Colorado State University. Libraries, 2016) Avila, Brian Walter, author; Winkelman, Dana L., advisor; Angeloni, Lisa M., committee member; Fetherman, Eric R., committee member; Myrick, Christopher A., committee memberMany animal populations have experienced population declines due to a broad range of factors such as habitat loss and degradation, invasive species, disease, and climate change. Introduced pathogens are known to have dramatic effects on populations. Following the establishment of the parasite that causes whirling disease (Myxobolus cerebralis) in Colorado, Colorado Parks and Wildlife (CPW) developed a whirling disease resistant Rainbow Trout (Oncorhynchus mykiss) for stocking known as the GRxCRR. The GRxCRR is a cross between the wild, susceptible Colorado River Rainbow (CRR) and the domesticated, resistant German Rainbow (GR) trout strains. It was thought that the GRxCRR would exhibit survival and reproduction similar to that of the CRR, overcome potential disadvantages associated with the history of domestication of the GR, and maintain the genetic resistance to whirling disease of the GR. One disadvantage to stocking GRxCRR is the potential for outcrossing and backcrossing that could decrease resistance to whirling disease. Stocking pure GR was not considered a viable option because it was thought that they would not survive well in a natural environment. However, in a laboratory study the GR and GRxCRR strains showed few physiological differences, indicating that the GR may be a candidate for stocking in whirling disease positive streams. I undertook a laboratory and field experiment to compare fry survival between the two strains. The field experiment was conducted in three drainages (Cache la Poudre River, Middle Fork of the South Platte River, and Colorado River), and three streams were selected in each drainage. One-mile reaches of each stream were stocked in August 2014 with 5,000 GRxCRR, identified with coded wire tags, and 5,000 untagged GR. In October 2014, April 2015 and August 2015, population estimates were conducted, providing an estimate of apparent survival for each strain. Two laboratory experiments were also conducted. In the first experiment, a 50:50 mix of GRxCRR and GR were stocked into large open mesocosms with one wild Brown Trout (Salmo trutta) predator. Survival was estimated over a 24-hour time period. The second experiment was similar, but I added treatments with or without cover. The field experiment revealed that apparent survival and growth rate was influenced by strain, stream, and primarily average temperature within the first year after stocking. After two months in the wild, the GRxCRR exhibited a higher growth rate than the GR, opposite of what is seen in the hatchery. However, after 12 months there was no significant difference in apparent survival or growth rate between the GR and GRxCRR. Laboratory experiments revealed that there were no differences in survival between the strains when confronted with Brown Trout predation. My results indicate that the GR may be a viable alternative for stocking in streams that contain M. cerebralis.