scholarly journals Molecular identification of water molds (oomycetes) associated with chum salmon eggs from hatcheries in Japan and possible sources of their infection

2019 ◽  
Vol 27 (6) ◽  
pp. 1739-1749
Author(s):  
Sakiko Orui Sakaguchi ◽  
Gen Ogawa ◽  
Hiroaki Kasai ◽  
Yuichi Shimizu ◽  
Hiroshi Kitazato ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Chum Salmon ◽  
Salmon Eggs

Infection of oomycetes and bacteria associated with their specific colocalization in chum salmon eggs

Aquaculture ◽  
2021 ◽  
pp. 737244
Author(s):  
Sakiko Orui Sakaguchi ◽  
Tetsuro Ikuta ◽  
Akihiro Tame ◽  
Yuichi Shimizu ◽  
Kiyotaka Takishita ◽  
...  
Keyword(s):  
Chum Salmon ◽  
Salmon Eggs

Scavenging by Alloperla (Plecoptera: Chloroperlidae) nymphs on dead pink (Oncorhynchus gorbuscha) and chum (O. keta) salmon embryos

1968 ◽  
Vol 46 (4) ◽  
pp. 787-796 ◽  
Author(s):  
Stephen J. Nicola
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Chum Salmon ◽  
Linear Regression Analysis ◽  
Oncorhynchus Gorbuscha ◽  
Beneficial Effects ◽  
Salmon Eggs ◽  
The Relationship

The relationship between stonefly nymphs of the genus Alloperla and developing pink and chum salmon embryos was studied in Harris River, Alaska, from August, 1965, to April, 1966. Polyethylene containers with alternating layers of salmon eggs and washed gravel and containers with washed gravel only were buried in sections of an upstream spawning riffle and were removed and examined in three sampling periods. Correlation and linear regression analysis of numbers of missing embryos, dead embryos, and stonefly nymphs in the containers supported the hypothesis that the nymphs were scavengers but failed to support the hypothesis that they were predators.Some of the beneficial effects to living embryos of scavenging by nymphs is discussed, as well as the likelihood of occurrence of predation by stonefly nymphs in general.

Twin malformation induced in chum salmon eggs by elevated water temperature, with a suggestion as to its mechanism

1996 ◽  
Vol 74 (3) ◽  
pp. 485-491 ◽  
Author(s):  
Tadashi S. Yamamoto ◽  
Wataru Kobayashi ◽  
Tsutomu Kuramoto
Keyword(s):  
Embryonic Development ◽  
Early Phase ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Egg Activation ◽  
Cell Stage ◽  
Salmon Eggs ◽  
Previously Treated ◽  
Cortical Vesicles ◽  
Elevated Water

Inseminated eggs of chum salmon, Oncorhynchus keta, were incubated at 18 °C. In batches of eggs from different females, we regularly observed twinning in a proportion of the eggs (0.5–4%) continuously incubated at this temperature, although no twins were obtained at 8 °C. Twinning was, however, observed at 8 °C when inseminated eggs had been previously treated at 18 °C until the 2- to 4-cell stage. In contrast, eggs attaining telophase in the second meiosis at 8 °C did not show the twin malformation, even when they continued embryonic development at 18 °C. In sections of eggs developed as twins, we detected accumulations of PAS-positive vesicular bodies in the ooplasm between the two embryos. A small number of eggs showing impaired exocytosis of cortical vesicles (alveoli) during egg activation developed into twins. A similar malformation was also induced after part of the ooplasm was dislodged in activated eggs. We propose that vesicular bodies interfere with the convergent migration of the axial determinant during the early phase of embryonic development, which leads to the formation of multiple morphogenetic centers in the eggs incubated at 18 °C.

Comment on “Egg consumption in mature Pacific salmon (Oncorhynchus spp.)”Appears in Can. J. Fish. Aquat. Sci. 66(9): 1546–1553.

2010 ◽  
Vol 67 (12) ◽  
pp. 2052-2054 ◽  
Author(s):  
Jonathan B. Armstrong
Keyword(s):  
Recent Article ◽  
Chum Salmon ◽  
Pacific Salmon ◽  
Stomach Contents ◽  
Energy Budgets ◽  
Egg Consumption ◽  
Salmon Eggs ◽  
Consumption Rates

In their recent article, “Egg consumption in mature Pacific salmon ( Oncorhynchus spp.)” (Can. J. Fish. Aquat. Sci. 66(9): 1546–1553), Garner et al. observed salmon eggs in the stomach contents of mature Chinook, coho, and chum salmon. Through experimentation and simulation of salmon energetics, the authors conclude that the observed feeding represents an important gain in energy, challenging the accepted paradigm that assumes salmon energy budgets contain no gains once adults return to freshwater. Here, I argue that Garner et al. have overestimated the energetic consequence of egg consumption and that the observed consumption rates do not represent biologically significant gains in energy.

Results for Three Generations from Transfers of Pink Salmon (Oncorhynchus gorbuscha) Spawn to the Qualicum River in 1963 and 1964

1971 ◽  
Vol 28 (5) ◽  
pp. 647-654 ◽  
Author(s):  
C. E. Walker ◽  
D. B. Lister
Keyword(s):  
Chum Salmon ◽  
Pink Salmon ◽  
Stream Temperature ◽  
Rate Of Return ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Three Generations ◽  
Salmon Eggs ◽  
Bear River

Transfers of pink salmon (Oncorhynchus gorbuscha) eggs were made to the Qualicum River in two years, utilizing 5.79 million eggs from Cheakamus River stock in 1963 and 6.85 million eggs from Bear River stock in 1964. Adult returns to the Qualicum River were 100 spawners in 1965, 1967, and 1969; 11,940 in 1966; 3000 in 1968; and 300 in 1970. Differences between the odd- and even-year plants were noted in times of egg-take (equivalent to time of spawning of donor stock), incubation, and fry emigration, lengths of emigrating fry, possibility of losses through predation by herring on estuarine fry, and direction of orientation to the recipient (Qualicum River) stream. Pronounced differences between donor stock in rate of return are thought to be primarily related to differences in spawning times and stream temperature. The decrease in numbers of adults in the even-year generation may have been due to lower freshwater survival during incubation as a result of suspected superimposition of chum salmon on the earlier deposited pink salmon eggs; the loss was estimated to be in the order of 46%.

Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity

2003 ◽  
Keyword(s):  
Chum Salmon ◽  
Puget Sound ◽  
Song Sparrow ◽  
Oncorhynchus Keta ◽  
Spawning Period ◽  
Felis Concolor ◽  
Salmon Eggs ◽  
Lutra Canadensis ◽  
Nitrate And Nitrite ◽  
Salmon Carcasses

<em>Abstract.</em>—During 1997–2000, chum salmon <em>Oncorhynchus keta </em>spawners and their predators and scavengers were observed in lower Kennedy Creek, a small south Puget Sound, Washington stream. Chum salmon occupy 5.2 km of main Kennedy Creek and a small tributary called Fiscus Creek. Spawning escapements within this stream averaged 39,000 fish annually during this study. Active spawning began in late October and was over by mid- December. Direct consumption of live and dead salmon was observed or inferred from animal signs over the spawning period. Salmon carcasses and tissue fragments could be found scattered along the streambed from October through March, and bones remained year round. Live spawners, carcass flesh, and eggs were consumed by 30 species of birds, mammals, invertebrates, and fungi, including 9 previously undocumented species. High carcass densities allowed selective feeding for some consumers and opportunistic feeding for others. Apparent preferences for eggs by several consumers suggested another important role for naturally spawning salmon. Varied thrush <em>Ixoreus naevius</em>, otter <em>Lutra canadensis</em>, and song sparrow <em>Melospiza melodia </em>showed preferences for salmon eggs, and a cougar <em>Felis concolor </em>killed live salmon and fed on them. Some consumers coordinate successive utilization of carcasses, such as the gull <em>Larus </em>spp., terrestrial beetle <em>Agyrtidae</em>, raccoon <em>Procyon lotor</em>, fly maggots, and mice. Water samples taken from the anadromous areas of these creeks and from the estuary in Totten Inlet showed elevated levels of dissolved ammonium, nitrate, and nitrite. Benefits to chum fry were inferred.

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