رسالة جامعية
Impacts of multispecies parasitism on coho salmon (Oncorhynchus kisutch) in Oregon
| العنوان: | Impacts of multispecies parasitism on coho salmon (Oncorhynchus kisutch) in Oregon |
|---|---|
| المؤلفون: | Ferguson, Jayde A. |
| المساهمون: | Kent, Michael, Jacobson, Kym, Schuster, Martin, Heidel, Jerry, Schreck, Carl, Microbiology, Oregon State University. Graduate School |
| بيانات النشر: | Oregon State University |
| المجموعة: | ScholarsArchive@OSU (Oregon State University) |
| مصطلحات موضوعية: | Coho salmon -- Mortality -- Oregon, Myxozoa -- Oregon, Coho salmon -- Parasites -- Oregon -- Geographical distribution, Coho salmon -- Oregon -- Growth, Coho salmon -- Parasites -- Oregon |
| الوصف: | Diseases caused by parasites are recognized as significant sources of mortality in wild fish populations. I assessed the impacts of multispecies parasitism on a threatened stock of juvenile coho salmon (Oncorhynchus kisutch). A crucial prerequisite to this research was proper identification of parasites, which can be difficult for species lacking distinct morphological features. Such was the case when I attempted to identify larval Apophallus sp. (Digenea) and a myxozoan infecting peripheral nerves, which I described as Myxobolus fryeri. The second essential step was to document the geographic distribution of infections in Oregon coastal juvenile coho salmon. I found 21 different parasite species in underyearlings and smolts from 10 different rivers. Some parasites, such as Apophallus sp., were more common in underyearlings than smolts and had a more restricted geographic distribution. Additionally, I empirically compared histology to the evaluation of wet preparations for parasite detection. The latter was more sensitive, but the former provided data on tissue level impacts. I then focused my research on parasitized coho salmon from one river, the West Fork Smith River (WFSR). The lower abundance of some parasites in smolts, compared to underyearlings suggested parasite associated mortality. Therefore, I evaluated the persistence of these parasites, as this trend could also be explained by infection recovery. The parasites in my study persisted throughout the overwintering period of these coho salmon. I also conducted a field study involving both pseudolongitudinal and retrospective approaches. Results indicated that up to 95% of parr from the lower mainstem of the WFSR had infections levels of Apophallus sp. that were associated with mortality. I also performed a laboratory study on wild fish from two consecutive year classes and fish experimentally infected with Nanophyetus salmincola. Parasite associations were evaluated for the following fish performances: size, growth, swimming stamina, and gill ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| اللغة: | English unknown |
| العلاقة: | https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/w3763965vTest |
| الإتاحة: | https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/w3763965vTest |
| حقوق: | All rights reserved |
| رقم الانضمام: | edsbas.7F0FB1C1 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |