Effects of transferring pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon embryos at different developmental stages to a low incubation temperature

1987 ◽  
Vol 65 (1) ◽  
pp. 96-105 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray

We transferred embryos of pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon from 8 to 2 °C at five stages of development: 16-cell stage, blastula stage, completion of epiboly, early eye pigmentation, and late eye pigmentation. Survival rates of the embryos increased the later in development that they were transferred to 2 °C. All pink salmon blastulas transferred died, whereas 50% of chum salmon blastulas transferred survived until hatching. After epiboly was complete, survival rates of the embryos subsequently transferred to 2 °C were usually in excess of 75%. Chum salmon embryos had higher survival rates than did pink salmon embryos at all transfer stages. Significant differences were found in embryo survival rates among stocks within species and among families within stocks. Fry from early-spawning chum salmon took longer for exogenous yolk absorption ("button-up") than did those from late-spawning ones. Alevins and fry from early transfers were generally smaller than those from later ones. Different trends in embryo and alevin survival rates and alevin and fry size among stocks within species and among families within stocks were assumed to be indicative of adaptive variation to variable natural incubation environments.


Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Terry D. Beacham

A factorial mating design was employed in which five males were mated to each of five females in each of two stocks for both pink and chum salmon. The resulting embryos and alevins were incubated at constant water temperatures of 4, 8, and 16 °C for pink salmon and 3, 8, and 15 °C for chum salmon. Variation among families in alevin and fry survival rates, hatching, button-up time, length, and weight was the least at 8 °C. Heritability of traits directly correlated with fitness, such as survival rates and button-up time, was low at all temperatures (h2 ≤ 0.25). Maternal effects could account for a substantial portion of the variation in alevin and fry size characters. Nonadditive genetic variance accounted for more of the variation in fry size characters than in those of alevins. Negative genetic correlations were observed between embryo survival and subsequent alevin size and between hatching time and subsequent alevin and fry size. Genotype–temperature interactions could underlie a substantial amount of phenotypic variation in the developmental characters examined for both species.Key words: development, genetic variation, quantitative genetics, salmon.



1984 ◽  
Vol 41 (10) ◽  
pp. 1446-1453 ◽  
Author(s):  
William W. Smoker

Different stock dynamics result from genetic and nongenetic mechanisms of determination of maturation age of chum salmon (Oncorhynchus keta) in a model of interacting pink (O. gorbuscha) and chum salmon stocks. When the model is disturbed from equilibrium by low survival in one pink salmon line, the genetic mechanism (high heritability of maturation age) leads to biennial cycles of numbers of even-aged chums and of numbers of pinks, similar to observed cycles. The nongenetic mechanism (zero heritability of maturation age) results in a new equlibrium at which neither stock cycles. When one pink salmon line is completely removed the genetic mechanism leads to biennial cycles of abundance of even-aged chums; the nongenetic mechanism does not lead to such cycles. These effects persist at intermediate values of heritability of maturation age and in spite of stochastic variability. The model is an adaptation of the Ricker curve to two interacting stocks, the recruitment for each depending on the density of both.



1985 ◽  
Vol 42 (11) ◽  
pp. 1755-1765 ◽  
Author(s):  
Terry D. Beacham ◽  
Clyde B. Murray

We incubated eggs and alevins for five chum salmon (Oncorhynchus keta) families in each of three female size classes under controlled water temperatures of 4, 8, and 12 °C. Egg survival from fertilization to hatching was highest for eggs from small females and lowest for eggs from large females at all three incubation temperatures. Egg survival was highest at 8 °C, and at 4 °C survival rates were largely determined from fertilization to epiboly, but at 12 °C the lowest egg survival rates were recorded from eye pigmentation to hatching. There were marked differences in egg survival rates among families. Overall survival rates from egg fertilization to fry emergence were most divergent between the large and small female size class at 12 °C. Hatching time of the alevins and emergence time of the fry were similar among the three female size classes at each incubation temperature. Alevins hatching at 4 °C were the longest, but those hatching at 12 °C were the heaviest. Larger females produced alevins with both more yolk reserves and more body tissue at hatching than those from smaller females. The relation between egg weight and subsequent alevin size was dependent upon incubation temperature. At emergence, the longest and heaviest fry were produced by the largest female size class.



2006 ◽  
Vol 120 (2) ◽  
pp. 199
Author(s):  
Alexandra Morton ◽  
Rob Williams

Recent recurring infestations of Sea Lice, Lepeophtheirus salmonis, on juvenile Pacific salmon (Oncorhynchus spp.) and subsequent annual declines of these stocks have made it imperative to identify the source of Sea Lice. While several studies now identify farm salmon populations as sources of Sea Louse larvae, it is unclear to what extent wild salmonid hosts also contribute Sea Lice. We measured Sea Louse numbers on adult Pink Salmon (Oncorhynchus gorbuscha) migrating inshore. We also measured Sea Louse numbers on wild juvenile Pink and Chum salmon (Oncorhynchus keta) migrating to sea before the adults returned, and as the two age cohorts mingled. Adult Pink Salmon carried an average of 9.89 (SE 0.90) gravid lice per fish, and thus were capable of infecting the adjacent juveniles. Salinity and temperature remained favourable to Sea Louse reproduction throughout the study. However, all accepted measures of Sea Louse infestation failed to show significant increase on the juvenile salmon, either in overall abundance of Sea Lice or of the initial infective-stage juvenile lice, while the adult wild salmon were present in the study area. This study suggests that even during periods of peak interaction, wild adult salmon are not the primary source of the recent and unprecedented infestations of Sea Lice on juvenile Pacific Pink and Chum salmon in the inshore waters of British Columbia.



2007 ◽  
Vol 116 (4) ◽  
pp. 298-304 ◽  
Author(s):  
R.B. Phillips ◽  
J. DeKoning ◽  
M.R. Morasch ◽  
L.K. Park ◽  
R.H. Devlin


1988 ◽  
Vol 66 (1) ◽  
pp. 266-273 ◽  
Author(s):  
C. B. Murray ◽  
J. D. McPhail

Embryo and alevin survival, time to hatching and emergence, and alevin and fry size of five species of Pacific salmon (Oncorhynchus) were observed at five incubation temperatures (2, 5, 8, 11, and 14 °C). No pink (Oncorhynchus gorbuscha) or chum (O. keta) salmon embryos survived to hatching at 2 °C. Coho (O. kisutch) and sockeye (O. nerka) salmon had higher embryo survival at 2 °C than chinook (O. tschawytscha) salmon. At 14 °C, chum, pink, and chinook salmon had higher embryo survival than coho or sockeye salmon. In all species, peaks of embryo mortality occurred at specific developmental stages (completion of epiboly, eye pigmentation, and hatching). Alevin survival to emergence was high for all species, except for coho and pink salmon at 14 °C. Hatching and emergence time varied inversely with incubation temperature, but coho salmon hatched and emerged sooner at all temperatures than the other species. Coho and sockeye salmon alevins were larger at 2 °C, pink, chum, and chinook salmon alevins were larger at 5 and 8 °C. Coho salmon fry were larger at 2 °C, chinook and chum salmon fry were larger at 5 °C, and sockeye and pink salmon fry were larger at 8 °C. High incubation temperatures reduced fry size in all species. Each species of Pacific salmon appears to be adapted to different spawning times and temperatures, and thus indirectly to specific incubation temperatures, to ensure maximum survival and size and to maintain emergence at the most favorable time each year.



1986 ◽  
Vol 64 (3) ◽  
pp. 670-676 ◽  
Author(s):  
Clyde B. Murray ◽  
Terry D. Beacham

Eggs and alevins from six odd-year, brood-line stocks of pink salmon (Oncorhynchus gorbuscha) spawning in southern British Columbia were incubated under varying temperature regimes and subjected to rapid temperature changes at specific developmental stages. Increasing or decreasing temperature regimes had no significant effect on egg and alevin survival. The inclusion of 2 or 4 °C in the temperature regime reduced egg survival. Rapid temperature changes from 12 to 1 °C late in development reduced alevin survival when compared with transfers from 8 to 1 °C. Hatching and emergence time varied inversely with mean incubation temperature. Decreasing temperature regimes produced longer and heavier alevins and fry than increasing temperature regimes. Low mean incubation temperatures from fertilization to fry emergence resulted in longer and heavier alevins and fry than those at higher mean temperature. Transfers from 8 or 12 °C to 1 °C early in development had a greater effect on alevin length and weight than transfers late in development. Temperature regimes can be manipulated to enhance survival, control development time, and increase alevin and fry size.



2021 ◽  
Vol 201 (3) ◽  
pp. 702-711
Author(s):  
O. V. Zelennikov ◽  
T. A. Schneider ◽  
M. Yu. Stekolshchikova

State of blood cells is examined for juveniles of pink and chum salmon sampled from Lesnoy Pugachevsky, Taranaisky and Okhotsky hatcheries in Sakhalin in May-June of 2018 and 2019 and caught in the Ochepukha, Pugachevka and Taranay Rivers during their catadromous migration to the sea. Both hatchery and wild juveniles of both species were characterized by high adaptive capabilities evidenced with high content of young forms of erythrocytes in the blood (17.0–31.0 %), significant portion of lymphocytes (60.8–92.0 %), and small number of neutrophils. The high adaptive capabilities were confirmed in the experiment, when juveniles of pink salmon were placed in the seawater without preliminary acclimation, but noticeable changes in the state of blood cells were not revealed both for wild and hatchery-reared specimens. Proportion of different blood cells was highly variable for juveniles of both artificial and natural origin but was more similar between the fry hatched at the same hatcheries or in the same rivers. A case of increased number of neutrophils was noted in 2019 for certain groups of juveniles, with total increasing of platelets in the blood that was explained by an external influence on the juveniles.



2010 ◽  
Vol 84 (4) ◽  
pp. 434-440 ◽  
Author(s):  
J. Suzuki ◽  
R. Murata ◽  
K. Sadamasu ◽  
J. Araki

AbstractWe investigated the risk of diphyllobothriasis from ingestion of wild Pacific salmon in Japan by surveying Diphyllobothrium plerocercoids in 182 salmon samples obtained from Japan. The plerocercoids were not detected in chum salmon (Oncorhynchus keta) (0/26), called Akizake in Japan, caught between September and November. However, the detection rate of plerocercoids in chum salmon, called Tokishirazu in Japan, caught between early April and June, was 51.1% (24/47) with an average of two plerocercoid larvae per fish. The detection rates of cherry salmon (Oncorhynchus masou) and pink salmon (Oncorhynchus gorbuscha) were 12.2% (10/82) and 18.5% (5/27), respectively, and the average number of plerocercoids per fish was 0.45 (37 larvae/82 fishes) and 0.22 larvae (6 larvae/27 fishes), respectively. Plerocercoids isolated from O. keta and O. masou were identified as Diphyllobothrium nihonkaiense on the basis of molecular analysis of the cox1 and nad3 genes. Moreover, four tapeworms (three from O. keta and one from O. masou) were obtained by infecting golden hamsters with plerocercoids. The morphological features of these tapeworms were similar to those of D. nihonkaiense isolated from humans. Therefore, we think that O. keta and not O. masou is the most important source of plerocercoid infections in Japan.



2006 ◽  
Vol 63 (9) ◽  
pp. 2076-2086 ◽  
Author(s):  
Morgan D Hocking ◽  
Thomas E Reimchen

Anadromous Pacific salmon (Oncorhynchus spp.) subsidize terrestrial food webs with their nutrients and carcasses, a process driven largely by selective foraging by bears (Ursus spp.). We quantify wildlife transfer of salmon carcasses to riparian zones on two watersheds in coastal British Columbia and estimate total terrestrial fly production from remnant carcasses. Large-bodied chum salmon (Oncorhynchus keta) were transferred into the forest at a greater rate than were pink salmon (Oncorhynchus gorbuscha) (chum salmon mass = 6089–11 031 kg, 16%–48% of salmon run; pink salmon mass = 2266–2808 kg, 4%–6% of salmon run). Blow flies (genus Calliphora) and other Diptera dominated colonization (>90% of salmon carcasses). Between the two watersheds, 196 and 265 g of Calliphora larvae per metre of spawning length (4 and 7 million larvae for whole watersheds) were generated from salmon carcass transfer. Stable isotope analysis of δ15N and δ13C of spring-emerging adult Calliphora revealed that >80% of individuals had salmon-based signatures. Flies are a dominant consumer and vector of salmon nutrients in terrestrial habitats and supplement the diet of at least 16 vertebrate and 22 invertebrate species. Anticipated further declines of salmon in the North Pacific can be expected to further erode the complex associations coupling marine and terrestrial ecosystems.



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