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.

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

scholarly journals Resources and fishery of Pacific salmon in Magadan region in the beginning of the 21st century

Trudy VNIRO ◽  
2020 ◽  
Vol 179 ◽  
pp. 90-102
Author(s):  
M. N. Gorokhov ◽  
V. V. Volobuev ◽  
I. S. Golovanov
Keyword(s):  
Chum Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Spawning Grounds ◽  
Magadan Region ◽  
Spawning Areas ◽  
Optimal Values ◽  
In The Beginning ◽  
Salmon Fishery

There are two main areas of pacific salmon fishing in the Magadan region: Shelikhova Gulf and Tauiskaya Bay. The main fishing species is pink salmon in the region. Its share of total salmon catch by odd-year returns reaches 85 %. Data on the dynamics of escapement to the spawning grounds of pink salmon of the Shelikhova Gulf and Tauiskaya Bay are presented. The displacement of the level of spawning returns of pink salmon into the Shelihova Gulf with the simultaneous reduction of its returns to the Tauiskaya Bay is shown. Data on the dynamics of the fishing indicators of pink salmon for the two main fishing areas are provided. The Tauiskaya Bay as the main pink salmon fishery area loses its importance is shown. Graphical data on the escapement of producers pink salmon to the spawning grounds are presented and the optimal values of spawning escapements are estimated. Chum salmon is the second largest and most fishing species. Information on the dynamics of the number of returns, catch and escapement to the spawning grounds of chum salmon is given. The indicators of escapement to the spawning areas and their compliance with the optimal passes of salmon producers are analyzed. The issues of the dynamics of returns number, catch and the escapement to the spawning grounds of coho salmon producers are considered. The level of the escapement to the spawning areas is shown and the ratio of actual to optimal values of passes is estimated. The role of coho salmon as an object of industrial fishing and amateur fishing is shown. The extent of fishing press on individual groups of salmon populations is discussed. It is concluded that it is necessary to remove the main salmon fishery from the Tauiskaya Bay to the Shelikhova Gulf.

Fine structure of the external egg membrane of five species of Pacific salmon and steelhead trout

1985 ◽  
Vol 63 (3) ◽  
pp. 552-566 ◽  
Author(s):  
E. P. Groot ◽  
D. F. Alderdice
Keyword(s):  
Fine Structure ◽  
Chum Salmon ◽  
Pacific Salmon ◽  
Salmo Gairdneri ◽  
Membrane Thickness ◽  
Steelhead Trout ◽  
Outermost Layer ◽  
Additional Layer ◽  
Egg Membrane ◽  
Pore Canals

Fine structure of the external egg membrane of five species of Pacific salmon (sockeye, Oncorhynchus nerka; pink, O. gorbuscha; chum, O. keta; coho, O. kisutch; and chinook, O. tshawytscha) and the anadromous steelhead trout (Salmo gairdneri), is examined and compared using the scanning electron microscope. Membrane thickness in fixed material varies for the six species as follows (micrometres, [Formula: see text]): sockeye, 34.15 ± 0.15; pink, 61.64 ± 1.53; chum, 53.05 ± 0.33; coho, 27.96 ± 0.48; chinook, 50.82 ± 0.74; steelhead, 30.74 ± 0.11. The membrane consists of a thin outermost layer, the externus, 0.2–0.3 μm thick, and the internus, 24–55 μm thick, which constitutes the remainder of the membrane. In sockeye, pink, and chum salmon and steelhead trout, an additional layer 3–8 μm thick, the "subinternus," occurs beneath the internus. The entire membrane appears fibrous except for the thin and apparently solid externus. Pores in both the inner and outer surfaces are arranged in a hexagonal pattern and are connected by pore canals traversing the membrane. Except in the sockeye, plugs commonly were seen blocking the external openings of the pore canals. Significance of the egg membrane fine structure is considered in relation to several of its roles in the water-activated egg: semipermeability, retention of internal pressure, and mechanical protection. A structural and functional analogy is drawn between the fine structure of the salmonid egg membrane and the mammalian aorta.

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.

Amino acid cues emanating from Pacific salmon eggs and ovarian fluid

2020 ◽  
Vol 97 (5) ◽  
pp. 1408-1414
Author(s):  
Andrew H. Dittman ◽  
Thomas P. Quinn
Keyword(s):  
Amino Acid ◽  
Pacific Salmon ◽  
Ovarian Fluid ◽  
Salmon Eggs

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.

Reactions of Juvenile Pacific Salmon to Light

1957 ◽  
Vol 14 (6) ◽  
pp. 815-830 ◽  
Author(s):  
W. S. Hoar ◽  
M. H. A. Keenleyside ◽  
R. G. Goodall
Keyword(s):  
Chum Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Low Light ◽  
Salmon Fry ◽  
Experimental Apparatus ◽  
Schooling Behaviour ◽  
Marked Preference ◽  
Juvenile Pacific Salmon ◽  
Changing Light

When given a choice between light and dark areas, schools of chum or pink salmon fry remain in the light, sockeye fry prefer the dark and coho fry show no marked preference for either. Newly emerged sockeye fry are the most strongly photonegative, remaining mostly under stones. Older sockeye fry move more into the light. Sockeye and coho smolts stay in the dark more than sockeye and coho underyearlings. Territorial and "escape" behaviour by fish in the experimental apparatus may obscure these reactions to light. Soon after emerging from the gravel, pink fry swim near the surface under low light intensity and retreat to deeper water in brighter light. Older pink fry seem indifferent to changing light. Recently emerged chum salmon fry do not respond in this way to changing illumination, although older fry tend to swim closer to the surface. This difference between pink and chum salmon fry may be related to differences in schooling behaviour and alarm responses of the two species.

Stomach Contents of Salmon and Steelhead Trout in the Northeastern Pacific Ocean

1966 ◽  
Vol 23 (1) ◽  
pp. 85-100 ◽  
Author(s):  
R. J. LeBrasseur
Keyword(s):  
Pacific Ocean ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Pink Salmon ◽  
Stomach Contents ◽  
Northwestern Pacific ◽  
Steelhead Trout ◽  
Fish Size ◽  
Northeastern Pacific

Stomachs of pink, chum, sockeye, and coho salmon and steelhead trout caught during the summer of 1958 in gillnets fished overnight in the northeastern Pacific Ocean contained mainly zooplankton (Limacina, amphipods, copepods, and euphausiids), squid, and fish. Except for sockeye, there were no differences in contents related to fish size or state of maturity. Differences were found between species in the kinds of stomach contents present. The predominant organisms were amphipods and fish in pink salmon, crustaceans in immature sockeye, euphausiids and squid in maturing sockeye, euphausiids, fish, and squid in coho, and fish and squid in steelhead stomachs. The stomach contents of chum salmon were notable in that most of their contents were too well digested to identify. Comparison with the findings of workers in the northwestern Pacific showed no significant differences in the kinds of stomach contents, however, a greater amount of material was present in the stomachs they examined. The contents of stomachs from fish taken in various ocean domains were compared. Greater differences were noted in the stomach contents of fish from different domains than from different species. It is suggested that feeding is associated more with availability rather than with preferences for specific organisms.

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