Thesis (M.S.)-Oregon State University, 1988. / Includes bibliographical references (leaves 74-80). Also available via the Internet.

Thesis (M.Sc.) - Carleton University, 2001. / Includes bibliographical references (p. 94-112). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 126-141). Also available via the World Wide Web.

Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains vi, 44 p. : ill. (some col.), map. Includes abstract. Includes bibliographical references (p. 28-35).

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains v, 33 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 30-33).

Thesis (Ph.D.)--McMaster University, 2005. / Advisor: Chris M. Wood Includes bibliographical references. Also available online.

A series of experiments were conducted to examine the effect of petroselinic acid, found in coriander oil, on fillet, hepatocyte and whole body FA composition and Δ6 desaturase gene expression in hepatocytes of rainbow trout (Oncorhynchus mykiss) fed vegetable oil (VO) based diets containing no fishmeal (FM) or fish oil (FO). In the first experiment, rainbow trout were fed one of eight diets containing fish, flax, canola or Camelina sativa oil with or without coriander oil. Coriander oil in the diet increased concentrations of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3, P < 0.05) in the fillet. There was a trend to increased 20:5n-3 + 22:6n-3/20:4n-6 ratios when coriander oil was added to the diet (P = 0.067). The second trial set out to investigate the effects of varied levels of coriander oil in canola oil based diets, on i) the capacity of rainbow trout hepatocytes to desaturate, elongate and esterify [1-14C] α-linolenic acid (18:3n-3; ALA) and [1-14C] linoleic acid (18:2n-6, LA), ii) reducing the production of 20:4n-6 in hepatocytes and iii) gene expression. This experiment demonstrated a significant increase in 22:6n-3 (P = 0.011) and a decrease 20:4n-6 (P = 0.023) in rainbow trout hepatocytes. Furthermore, there was a three-fold decrease in acetate for the [1-14C] 18:2n-6 and nearly a two-fold increase for the [1-14C] 18:3n-3 substrate when coriander was added at increasing levels, illustrating an increase in peroxisomal β-oxidation. Relative gene expression of ∆6 desaturase decreased with addition of coriander oil at the 0.5 inclusion level of coriander oil. The final experiment was conducted to determine if bypassing the first ∆6 desaturase and rate-limiting step in the n-3 FA pathway causes increased conversion of stearidonic acid (SDA; 18:4n-3) to 20:5n-3 and 22:6n-3. Rainbow trout were fed one of six diets containing either fish, conventional linseed (flax), or SDA enriched linseed oil (LO) with and without coriander oil. Inclusion of coriander oil did not affect any growth or feed intake parameters of rainbow trout. However, the addition of coriander oil caused a significant increase in whole body 22:6n-3 and 20:4n-6 concentrations in fish fed SDA enriched LO with coriander oil (SDA+C) compared to fish fed conventional linseed oil (LO). These results suggest that petroselinic acid, found in coriander oil, has the ability to influence FA bioconversion of the n-3 and n-6 FA pathway thereby increasing 22:6n-3 and possibly 20:5n-3 in rainbow trout and reducing ARA when fed VO-based diets. Furthermore, it seems as though petroselinic acid causes improved bioconversion to 22:6n-3 when the first ∆6 desaturase is bypassed. Further studies are needed to determine the mechanism of action that petroselinic acid has on FA bioconversion.

In freshwater fish, such as the rainbow trout (Oncorhynchus mykiss), higher ion concentrations in the body fluids relative to the dilute surrounding environment lead to diffusive ion loss that is countered by active ion uptake. Active ion uptake is achieved via specialised cells in the gill epithelium known as ionocytes, with the species studied to date exhibiting multiple ionocyte subtypes with specific complements of ion transport proteins. To better understand the functions and responses of each ionocyte subtype, methods are needed to isolate specific ionocyte subtypes. This thesis developed a method to use fluorescence-activated cell sorting (FACS) to isolate the peanut lectin agglutinin-positive (PNA+) ionocyte subtype of the trout gill, which is posited to be a base-secreting cell that takes up Cl- ions. A suspension of gill cells dissociated using ethylenediaminetetraacetic acid (EDTA) was labelled with biotinylated PNA that was detected using streptavidin conjugated to a fluorophore, and subjected to FACS to yield a population of PNA+ ionocytes of high viability and purity. To validate the utility of the approach, it was used in a proof-of-principle experiment to evaluate transcript abundance of cytosolic carbonic anhydrase (CAc) in PNA+ ionocytes in trout that were subjected to metabolic alkalosis. This experiment revealed that the relative transcript abundance of CAc was significantly elevated in PNA+ ionocytes of alkalotic trout relative to that of control trout (P = 0.001; N = 7), a response that is consistent with the expected role of PNA+ ionocytes in compensation for systemic alkalosis.

The central objective of this thesis is to better understand early life history dynamics of salmonids in large regulated rivers. I studied spawning, incubating, and age-0 life stages of rainbow trout in the Lee’s Ferry reach of the Colorado River below Glen Canyon Dam, AZ. My first objective was to evaluate the effects of hourly fluctuations in flow on nearshore habitat use and growth of age-0 trout. Catch rates in nearshore areas were at least 2- to 4-fold higher at the daily minimum flow compared to the daily maximum and indicated that most age-0 trout do not maintain their position within immediate shoreline areas during the day when flows are high. Otolith growth increased by 25% on Sundays in one year of study, because it was the only day of the week when flows did not fluctuate. My second objective was to evaluate the effects of flow fluctuations on survival from fertilization to a few months from emergence (early survival). Fluctuations were predicted to result in incubation mortality rates of 24% in 2003 and 50% in 2004, when flow was experimentally manipulated to reduce trout abundance, compared to 5% in 2006 and 11% in 2007 under normal operations. Early survival increased by over 6-fold in 2006 when egg deposition decreased by at least 10-fold. Because of this strong compensatory dynamic, flow-dependent incubation mortality in experimental years was likely not large enough to reduce the abundance of age-0 trout. My final objective was to determine how flow, fish size and density effects habitat use, growth, and survival of age-0 trout. Apparent survival rates from July to November were 0.18 (2004), 0.19 (2006), and 0.32 (2007). A stock synthesis model was developed to jointly estimate parameters describing early life history dynamics, and indicated that early survival was lower for cohorts fertilized during the first half of the spawning period and was negatively correlated with egg deposition, that movement of age-0 trout from low- to high-angle shorelines increased with fish size, and that survival varied by habitat type and over time in response to flow changes from Glen Canyon Dam. / Science, Faculty of / Zoology, Department of / Graduate

There is an increasing scientific acceptance that fish may feel some sort of fear, pain and distress, which in turn feeds a growing concern for their welfare. Humans impact the wellbeing of a large number of fish in various ways, one of them being through research. Welfare legislation in the UK demand welfare considerations for all animals used in scientific procedures. Furthermore, welfare and enrichment needs for fish are included in the Appendix A of the European Convention for the Protection of Vertebrate Animals used for Experimental and Scientific Purposes. As fish are extensively used in research, changing their housing and husbandry to improve welfare is of importance, since fish kept in laboratories are most likely subjected to impoverished environments. Although enrichment programs have been shown to improve health and welfare in various animal species, little is known of their potential for application to juvenile rainbow trout. How best to improve barren experimental tanks for female juvenile rainbow trout used in regulatory research was the broad aim of this PhD. In this thesis, three enrichment strategies for rainbow trout have been examined, using physiological and behavioural welfare indicators. The first study assessed the effects of semitransparent shelters on trout welfare, and a clear message became evident; that shelters of this design should not be considered enrichment for rainbow trout as they had several significant negative impacts, indicating chronic stress in fish from shelter tanks relative to fish in a barren environment. The second study investigated impacts of reduced visual access to conspecifics in the same tank. Habitats with low visual contact between individuals have been suggested to reduce aggression for a range of species, and I have shown that visual barriers appeared to be beneficial to trout as well. The final experiment evaluated effects of high and low water currents on the wellbeing of rainbow trout, and results indicated increased fish welfare when water currents were supplied.