Thesis (M.S.)--Oregon State University, 1966. / Includes bibliographical references (leaves 58-61).

Thesis (M.S.)--Oregon State University, 1966. / Typescript. Includes bibliographical references (leaves 58-61). Also available electronically via World Wide Web in PDF format.

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographic references (leaves [165]-185).

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 132-154).

Young sockeye salmon (Oncorhynchus nerka) may occupy the epilimnion, thermocline or hypolimnion during lacustrine residence and may make extensive vertical migrations. Residence and migration over a range of pressure presents fish with certain physiological problems. Sockeye salmon meet these problems by adaptation, compromise and fortuity. Sockeye evidenced a tolerance to pressure in excess of 20 atmospheres, equivalent to a depth of water of 680 feet. Sockeye fry showed no behavioral response to pressure prior to initial filling of the swimbladder, but thereafter pressure induced compensatory swimming. Young sockeye proved to be dependent on atmospheric air for inflation of the swimbladder. The restrictions to vertical movement imposed by the swimbladder are minimized in sockeye by a relatively small bladder volume, little excess pressure within the bladder, the bladder being thin-walled and extensible and the inability of these fish to secrete gas into the bladder. When frightened, young sockeye sounded and expelled gas from the swimbladder. Gas expulsion was found to be under adrenergic control and retention of gas in the swimbladder under cholinergic control. During decompression with upward movement through thermally stratified water, gas disease or the "bends" is obviated by the rapid clearance of dissolved nitrogen from the blood stream. Young sockeye showed a tolerance to rapid decompression except under conditions permitting swimbladder gas to appear as emboli in the blood stream. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 143-149).

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 150-162).

Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [90]-107).

Thesis (Ph. D.)--University of Washington. / Bibliography: l. 97-105.

The life cycle of Phflonema oncorhynchi was studied in sockeye salmon, Oncorhynchus nerka, from Cultus Lake, British Columbia. Gravid female worms from the coelom of sockeye spawners burst in lake water releasing living first-stage larvae. These were ingested by Cyclops bicuspidatus and developed to the infective third stage in the haemocoele. Development required 17 days at 12 C or 70 days at 8 C. Each of six hatchery-reared sockeye fingerlings were fed 14-70 copepods infected with third-stage larvae. Fourth-stage larvae were recovered from the peritoneal tissues of four fingerlings when examined four to ten days after infection. The later stages of development were studied by maintaining naturally infected sockeye salmon for two years in freshwater. These had early fourth-stage larvae in the parietal peritoneum and tunica adventitia of the swim bladder when captured as downstream migrants at Cultus Lake. When the fish were 26 months old, late fourth-stage larvae were found in the peritoneal tissues. These moved into the coelom when the fish were 32 months old and moulted to the preadult stage. The comparative morphology of mature worms collected from B.C. salmonids was studied. The type species, Philonema oncorhynchi Kuitunen-Ekbaum, 1933 was obtained from the type host, Oncorhynchus nerka, in the type locality, Vancouver, B.C. Philonema were also obtained from salmonids with a freshwater life cycle in a landlocked area, Kootenay Lake, which was once contiguous with the type locality of Philonema agubernaculum Simon and Simon, 1936. The morphology was constant for worms found in different hosts and geographical areas. Size was an unreliable characteristic and appeared to be a host-dependent variation. The type specimens of Philonema agubernaculum Simon and Simon, 1936 were examined and no differences in morphology found. / Science, Faculty of / Zoology, Department of / Graduate