Differences in acquired and innate resistance among Pacific salmon (Oncorhynchus spp.) against the haemoflagellate Cryptobia salmositica and numbers delivered by the leech vector Piscicola salmositica

1995 ◽  
Vol 52 (S1) ◽  
pp. 1-6 ◽  
Author(s):  
S.M. Bower
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Elevated Temperatures ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Lytic Activity ◽  
Juvenile Chinook Salmon ◽  
Elevated Water ◽  
Plasma Factors

Susceptible juvenile chinook salmon (Oncorhynchus tshawytscha) were protected from otherwise lethal challenges with the haemoflagellate Cryptobia salmositica by acclimation to an elevated water temperature (20 °C). Following challenge at temperatures advantageous to the haemoflagellate (9–11 °C), surviving fish had plasma with enhanced acquired lytic activity against the parasite. In contrast, most coho salmon (Oncorhynchus kisutch) from a resistant stock survived up to three challenges with C. salmositica, without "immunization" at elevated temperatures. However, they acquired little or no lytic activity against the parasite, which survived in low numbers in some fish. Also, the chinook and coho salmon did not have innate plasma factors that lysed the parasite under in vitro conditions like those demonstrated in other salmonids. Thus, the mechanism(s) that protect the resistant O. kisutch from the pathogenic affects of C. salmositica are different from those identified in other fishes that are resistant to Cryptobia spp. A challenge of 105 flagellates per fish was suggested to be representative of the number of C. salmositica inoculated into a fish by one infected leech vector (Piscicola salmositica).

Changes in the Average Size and Average Age of Pacific Salmon

1981 ◽  
Vol 38 (12) ◽  
pp. 1636-1656 ◽  
Author(s):  
W. E. Ricker
Keyword(s):  
Growth Rate ◽  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Gill Nets ◽  
Growing Seasons ◽  
Mean Size ◽  
Average Size

Of the five species of Pacific salmon in British Columbia, chinook salmon (Oncorhynchus tshawytscha) and coho salmon (O. kisutch) are harvested during their growing seasons, while pink salmon (O. gorbuscha), chum salmon (O. keta), and sockeye salmon (O. nerka) are taken only after practically all of their growth is completed. The size of the fish caught, of all species, has decreased, but to different degrees and over different time periods, and for the most part this results from a size decrease in the population. These decreases do not exhibit significant correlations with available ocean temperature or salinity series, except that for sockeye lower temperature is associated with larger size. Chinook salmon have decreased greatly in both size and age since the 1920s, most importantly because nonmaturing individuals are taken by the troll fishery; hence individuals that mature at older ages are harvested more intensively, which decreases the percentage of older ones available both directly and cumulatively because the spawners include an excess of younger fish. Other species have decreased in size principally since 1950, when the change to payment by the pound rather than by the piece made it profitable for the gill-netters to harvest more of the larger fish. Cohos and pinks exhibit the greatest decreases, these being almost entirely a cumulative genetic effect caused by commercial trolls and gill nets removing fish of larger than average size. However, cohos reared in the Strait of Georgia have not decreased in size, possibly because sport trolling has different selection characteristics or because of the increase in the hatchery-reared component of the catch. The mean size of chum and sockeye salmon caught has changed much less than that of the other species. Chums have the additional peculiarity that gill nets tend to take smaller individuals than seines do and that their mean age has increased, at least between 1957 and 1972. That overall mean size has nevertheless decreased somewhat may be related to the fact that younger-maturing individuals grow much faster than older-maturing ones; hence excess removal of the smaller younger fish tends to depress growth rate. Among sockeye the decrease in size has apparently been retarded by an increase in growth rate related to the gradual cooling of the ocean since 1940. However, selection has had two important effects: an increase in the percentage of age-3 "jacks" in some stocks, these being little harvested, and an increase in the difference in size between sockeye having three and four ocean growing seasons, respectively.Key words: Pacific salmon, age changes, size changes, fishery, environment, selection, heritability

Production of germline transgenic Pacific salmonids with dramatically increased growth performance

1995 ◽  
Vol 52 (7) ◽  
pp. 1376-1384 ◽  
Author(s):  
Robert H. Devlin ◽  
Timothy Y. Yesaki ◽  
Edward M. Donaldson ◽  
Shao Jun Du ◽  
Choy-Leong Hew
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Cutthroat Trout ◽  
Transgenic Fish ◽  
Somatic Tissue ◽  
Growth Enhancement ◽  
Gene Construct ◽  
Average Size

Transgenic Pacific salmon have been produced by microinjection of a DNA construct consisting of chinook salmon (Oncorhynchus tshawytscha) growth hormone sequences driven by an ocean pout (Macrozoarces americanus) antifreeze protein promoter. This construct was retained in approximately 4% of fish derived from injected eggs, and resulted in dramatic enhancement of growth relative to controls. For coho salmon (O. kisutch) at 15 months of age, the average size of transgenic fish was more than 10-fold that of controls, with the largest fish more than 30-fold larger than nontransgenic siblings. Dramatic growth enhancement was also observed in transgenic rainbow trout (O. mykiss), cutthroat trout (O. clarki), and chinook salmon using this same gene construct. Transgenic coho salmon underwent precocious parr–smolt transformation during their first fall, approximately 6 months in advance of their nontransgenic siblings. At 2 years of age, five male transgenic coho salmon became sexually mature, and four of these transmitted the gene construct to sperm, the negative fish being transgenic in blood but not fin tissue. These results show that while some fish are mosaic for the gene construct in different tissues, most are transgenic in both germline and somatic tissue.

In vitro detection of functional humoral immunocompetence in juvenile chinook salmon (Oncorhynchus tshawytscha) using flow cytometry

2003 ◽  
Vol 15 (2) ◽  
pp. 145-158 ◽  
Author(s):  
Ruth H. Milston ◽  
Anthony T. Vella ◽  
Tawni L. Crippen ◽  
Martin S. Fitzpatrick ◽  
Jo-Ann C. Leong ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

Do chemically contaminated river estuaries in Puget Sound (Washington, USA) affect the survival rate of hatchery-reared Chinook salmon?

2014 ◽  
Vol 71 (1) ◽  
pp. 162-180 ◽  
Author(s):  
James P. Meador
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Life Stage ◽  
Puget Sound ◽  
Adult Life ◽  
Parallel Analysis ◽  
Differential Survival ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

This study examined the rate of survival for hatchery-reared, ocean-type juvenile Chinook salmon (Oncorhynchus tshawytscha) to the adult life stage in relation to contamination status for estuaries where they temporarily reside. The hypothesis tested here is that juvenile Chinook from Puget Sound (Washington, USA) area hatcheries exhibit differential survival as categorized by the state of contamination in their respective natal estuaries. Data were examined from 20 hatcheries that released fish to 14 local estuaries in the Greater Puget Sound area over 37 years (1972–2008). A parallel analysis was also conducted for coho salmon (Oncorhynchus kisutch) outmigrating from many of the same hatcheries. For all years combined, juvenile Chinook transiting contaminated estuaries exhibited an overall rate of survival that was 45% lower than that for Chinook moving through uncontaminated estuaries, which was confirmed when tested year by year. The results for coho originating from the same hatcheries and sharing a similar marine distribution indicated no substantial differences among estuaries. These observations have important implications for wild juvenile Chinook that spend more time in the estuary compared with hatchery-reared fish.

scholarly journals A comparison of infectious agents between hatchery-enhanced and wild out-migrating juvenile chinook salmon (Oncorhynchus tshawytscha) from Cowichan River, British Columbia

FACETS ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 695-721 ◽  
Author(s):  
Krishna K. Thakur ◽  
Raphaël Vanderstichel ◽  
Shaorong Li ◽  
Emilie Laurin ◽  
Strahan Tucker ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Chinook Salmon ◽  
Large Scale ◽  
Oncorhynchus Tshawytscha ◽  
Pacific Salmon ◽  
River System ◽  
Infectious Agents ◽  
Juvenile Chinook Salmon ◽  
Hatchery Fish ◽  
Juvenile Chinook

Infectious diseases are likely contributing to large-scale declines in chinook salmon stocks in the Pacific Northwest, but the specific agents and diseases involved, and the prevalences in migratory salmon, are mostly unknown. We applied a high-throughput microfluidics platform to screen for 45 infectious agents in 556 out-migrating juvenile chinook salmon, collected from freshwater (FW) and saltwater (SW) locations in the Cowichan River system on Vancouver Island, Canada, during 2014. Nineteen agents (5 bacterial, 2 viral, and 12 parasitic) were detected, with prevalences ranging from 0.2% to 57.6%. Co-infections between Candidatus Branchiomonas cysticola Toenshoff, Kvellestad, Mitchell, Steinum, Falk, Colquhoun & Horn, 2012, Paranucleospora theridion Nylund, Nylund, Watanabe, Arnesen & Kalrsbakk, 2010, and gill chlamydia, all associated with gill disease, were observed in SW samples. We detected agents known to cause large-scale mortalities in Pacific salmon ( Ceratonova shasta (Noble, 1950), Parvicapsula minibicornis Kent, Whitaker & Dawe, 1977), and agents only recently reported in Pacific salmon in BC ( Ca. B. cysticola, P. theridion, Facilispora margolisi Jones, Prosperi-Porta & Kim, 2012 and Parvicapsula pseudobranchicola Karlsbakk, Saether, Hostlund, Fjellsoy & Nylund, 2002). Wild and hatchery fish were most divergent in agent profiles in FW, with higher agent diversity in wild fish. Differences in prevalence largely dissipated once they converged in the marine environment, although hatchery fish may be infected by a greater diversity of agents sooner after ocean entry by virtue of their more rapid migration from nearshore to offshore environments.

Dispersal and productivity of Chinook (Oncorhynchus tshawytscha) and coho (Oncorhynchus kisutch) salmon colonizing newly accessible habitat

2015 ◽  
Vol 72 (3) ◽  
pp. 454-465 ◽  
Author(s):  
Joseph H. Anderson ◽  
Paul L. Faulds ◽  
Karl D. Burton ◽  
Michele E. Koehler ◽  
William I. Atlas ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Population Expansion ◽  
Fishing Mortality ◽  
Fish Ladder ◽  
Accessible Habitat ◽  
Over Time

Following construction of a fish ladder at Landsburg Diversion Dam on the Cedar River, Washington, USA, in fall 2003, we used DNA-based parentage to identify second generation Chinook (Oncorhynchus tshawytscha) and coho (Oncorhynchus kisutch) salmon as recruits that were produced above the dam or “strays” dispersing into the new habitat that were produced elsewhere. For both species, strays colonized immediately but decreased as a proportion of the total run over time. Chinook salmon strays were more numerous in years when the species was more abundant below the dam and included a much larger proportion of hatchery origin salmon than did coho salmon. Productivity, calculated as the ratio of female recruits sampled at the dam to female spawners, exceeded replacement in all four coho salmon cohorts but only two of five Chinook salmon cohorts, leading to more rapid population expansion of coho salmon. However, estimates of fishing mortality and recruitment into the Cedar River below the dam substantially increased Chinook salmon productivity estimates. Our results demonstrate that Pacific salmon are capable of rapidly recolonizing habitat made accessible by restoration and emphasize the importance of demographic exchange with preexisting populations during the transition from recolonization to self-sustainability.

The Use of 17 α-methyltestosterone for Promoting Weight Increases in Juvenile Pacific Salmon

1973 ◽  
Vol 30 (8) ◽  
pp. 1099-1104 ◽  
Author(s):  
J. R. McBride ◽  
U. H. M. Fagerlund
Keyword(s):  
Weight Gain ◽  
Chinook Salmon ◽  
Structural Changes ◽  
Coho Salmon ◽  
Condition Factor ◽  
Pacific Salmon ◽  
Juvenile Chinook Salmon ◽  
Test Fish ◽  
Juvenile Pacific Salmon ◽  
Juvenile Chinook

The effect of 17 α-methyltestosterone feeding on the weight of juvenile coho salmon (Oncorhynchus kisutch) and on the weight, length, and condition factor of juvenile chinook salmon (O. tshawytscha) was determined. Significant increases in weight and length but not in condition factor were noted at all levels of steroid tested. Coho fed rations containing 10 mg/kg of the steroid for 42 days showed a 29% net weight gain and chinooks fed 1 mg/kg of the hormone for 84 days exhibited a 17% net weight gain over the respective control groups.A marked thickening of the skin was noted in the coho retained on diets containing 10 and 50 mg/kg of the steroid. This alteration was most evident in those fish fed the highest concentrations of hormone for the longest period.In the coho, diets containing 10 or 50 mg/kg of the hormone evoked marked degenerative changes in the testes. Less drastic alterations were noted in the testes of the chinooks retained on the 1 mg/kg test ration for 84 days. No apparent structural changes were noted in the ovary of any of the test fish.

Costs of living for juvenile Chinook salmon (Oncorhynchus tshawytscha) in an increasingly warming and invaded world

2012 ◽  
Vol 69 (10) ◽  
pp. 1621-1630 ◽  
Author(s):  
Lauren M. Kuehne ◽  
Julian D. Olden ◽  
Jeffrey J. Duda
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Pacific Salmon ◽  
Multiple Stressors ◽  
Freshwater Ecosystems ◽  
Smallmouth Bass ◽  
Interactive Effects ◽  
Physiological Indicators ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

Rapid environmental change in freshwater ecosystems has created a need to understand the interactive effects of multiple stressors, with temperature and invasive predators identified as key threats to imperiled fish species. We tested the separate and interactive effects of water temperature and predation by non-native smallmouth bass ( Micropterus dolomieu ) on the lethal (mortality) and sublethal (behavior, physiology, and growth) effects for juvenile Chinook salmon ( Oncorhynchus tshawytscha ) in seminatural stream channel experiments. Over 48 h trials, there was no difference in direct predation with warmer temperatures, but significant interactive effects on sublethal responses of juvenile salmon. Warmer temperatures resulted in significantly stronger and more variable antipredator responses (surface shoaling and swimming activity), while physiological indicators (plasma glucose, plasma cortisol) suggested suppression of physiological mechanisms in response to the combined stressors. These patterns corresponded with additive negative growth in predation, temperature, and combined treatments. Our results suggest that chronic increases in temperature may not increase direct predation over short periods, but can result in significant sublethal costs with negative implications for long-term development, disease resistance, and subsequent size-selective mortality of Pacific salmon.

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