scholarly journals Gametogenesis of the Pacific salmon. 3. Comparative analysis of the state of gonads in juvenile Pacific salmon due to fertility formation

2019 ◽  
Vol 323 (4) ◽  
pp. 429-441
Author(s):  
O.V. Zelennikov
Keyword(s):  
Comparative Analysis ◽  
Mitotic Activity ◽  
Fresh Water ◽  
Fish Species ◽  
Germ Cells ◽  
Pacific Salmon ◽  
Juvenile Fish ◽  
Pink Salmon ◽  
The Pacific ◽  
Juvenile Pacific Salmon

The ovarian condition was studied in juveniles of six species of the Pacific salmon of different ages, taken for research at four hatcheries, as well as captured in lakes and rivers in the Sakhalin Province and Kamchatka Territory. The formation of the older generation of germ cells, consisting of previellogenic oocytes, in females of the Pacific salmon ends at the age of 0+, in pink salmon, with a mass of about 0.2–0.3 g, in other species, with a mass of about 1–2 g. In all species, the replenishment of this generation ceases during the habitat of juvenile fish in fresh water. After the formation of the older generation of germ cells is completed and its number reaches a certain level characteristic of each fish species, two oogenesis processes, that are not externally related to each other, continue to be carried out in the ovaries. The first process is the growth of the older generation oocytes, which develop relatively synchronously, varying 1.5–2 times in diameter. The second process is the mitotic reproduction of the gonies, their entry into meiosis, and subsequent resorption at the stage of pachytene and early diplotene. The mitotic activity of the gonies is minimal in females of the pink salmon, and, in fact, it is not detected in the fish caught in the coast. In females of other species, a decrease in both mitotic activity and initiation of new meiotic cycles does not occur during the entire period of their habitat in fresh water.

Use of the stratified-Petersen estimator in fisheries management: estimating the number of pink salmon (Oncorhynchus gorbuscha) spawners in the Fraser River

1998 ◽  
Vol 55 (2) ◽  
pp. 281-296 ◽  
Author(s):  
Carl James Schwarz ◽  
Carolyn Gail Taylor
Keyword(s):  
Pacific Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Fraser River ◽  
Differential Migration ◽  
Mark Recapture ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
The Pacific ◽  
Recent Developments

The simple-Petersen estimator is a well-known mark-recapture method to estimate animal abundance. Two key assumptions are equal catchability in both samples and complete mixing of tagged and untagged animals. If these are violated, severe bias can occur. The stratified-Petersen estimator can be used to account for some of the heterogeneity in catchability or mixing. In this paper, we first review recent developments in the stratified-Petersen experiment for fisheries audiences and demonstrate some of the practical problems that can occur that have not been discussed in the theoretical literature. Second, we present a case study to estimate the gross escapement of Fraser River pink salmon (Oncorhynchus gorbuscha) in 1991. The motivation for this study is a discrepancy of over 5 million fish between the estimates as derived by the Pacific Salmon Commission (PSC) (7.5 million fish based on a hydroacoustic method) and the Department of Fisheries and Oceans (DFO), Canada (13.0 million fish based on a mark-recapture method). One hypothesis put forward was that the discrepancy may be due to the use of a pooled-Petersen estimator when there is differential migration over time. The stratified-Petersen model suggests that little of this discrepancy can be explained by differential migration.

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.

SEX DIFFERENTIATION IN THE PACIFIC SALMON ONCORHYNCHUS KETA (WALBAUM)

1953 ◽  
Vol 31 (2) ◽  
pp. 73-79 ◽  
Author(s):  
J. G. Robertson
Keyword(s):  
Germ Cells ◽  
Chum Salmon ◽  
Pacific Salmon ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
The Other ◽  
Oncorhynchus Keta ◽  
Progressive Development ◽  
The Pacific ◽  
Female Phase

The differentiation of the gonad is described in chum salmon embryos and alevins. Contrary to classical findings in teleosts, sex differentiation in the chum salmon proceeds in the male or female direction without an intermediate female phase. From an initially indifferent gonad there is a progressive development of one sex or the other. The organ forms as a fold from the splanchnic mesoderm and, at the time of first appearance, contains primordial germ cells. These enlarge to form the definitive germ cells which, after a series of divisions, form smaller oogonia or spermatogonia. Oogonia are followed by primary and secondary (growing) oocytes, the appearance of which is the criterion of sex distinction. Spermatogonia continue to multiply but do not undergo growth in the alevin. The ovary develops an open endovarial canal and is supported by a prominent mesovarium. The testis remains small and, in the alevin, develops no ducts. It is suspended by a mesorchium.

THE EFFECT OF TSH AND ANTITHYROID SUBSTANCES ON SALINITY PREFERENCE AND THYROID ACTIVITY IN JUVENILE PACIFIC SALMON

1963 ◽  
Vol 41 (2) ◽  
pp. 307-319 ◽  
Author(s):  
Bertha Baggerman
Keyword(s):  
Thyroid Gland ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
Secretory Activity ◽  
Conversion Ratio ◽  
Sodium Thiocyanate ◽  
Thyroid Activity ◽  
Salinity Preference ◽  
Juvenile Pacific Salmon

Underyearling coho salmon treated with TSH showed a change from fresh- to saltwater preference, which was correlated with an increase in thyroid activity (as measured by the amount of radioiodine taken up by the gland and the conversion ratio).Under-yearling pink salmon treated with thiourea showed a change from salt-to freshwater preference, which was accompanied by a decrease in thyroid activity. In this species treatment with thiouracil and sodium thiocyanate also induced a change from salt- to freshwater preference.It is concluded that the secretory activity of the thyroid gland is intimately involved in the induction of changes in salinity preference, which, in their turn, are closely associated with the onset and end of the migration season.

scholarly journals Recent experience of surveying the spawning grounds of pacific salmons in the water bodies of Chukotka

2020 ◽  
Vol 200 (2) ◽  
pp. 270-291
Author(s):  
E. A. Shevlyakov ◽  
S. V. Shubkin
Keyword(s):  
Sockeye Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
River System ◽  
Aerial Survey ◽  
Water Bodies ◽  
Recent Experience ◽  
Spawning Grounds ◽  
The Pacific ◽  
First Time

Aerial survey of the pacific salmon spawning grounds was conducted in the water bodies of Chukotka belonged to the Bering Sea basin (the Anadyr, Velikaya, Tumanskaya Rivers and Meinypilgyno lake-river system) in 2019, for the first time since 1992. Total flight time was 35 hours, approximate length of the transects was 3,800 km. Number of the spawners was estimated as 660.7 . 103 ind. for chum salmon, 112.2 . 103 ind. for sockeye salmon, and 3678.0 . 103 ind. for pink salmon, features of their distribution are described.

Adult Biology of the River Lamprey (Lampetra ayresi) and the Pacific Lamprey (Lampetra tridentate) from the Pacific Coast of Canada

1980 ◽  
Vol 37 (11) ◽  
pp. 1906-1923 ◽  
Author(s):  
Richard J. Beamish
Keyword(s):  
Salt Water ◽  
Juvenile Fish ◽  
Pink Salmon ◽  
Adult Life ◽  
Fish Parasites ◽  
Late Winter ◽  
Average Life Span ◽  
Pacific Lamprey ◽  
River Lamprey ◽  
The Pacific

River lamprey (Lampetra ayresi) metamorphose in late July with downstream migration occurring in the following year from May to July. Once adults enter salt water they begin to feed immediately by consuming chunks of flesh primarily from herring and young salmon. From June until September they increase in size by an estimated 11–14 cm and 12–18 g. In 1975, 667 000 lamprey were estimated to be in the Strait of Georgia resulting in the deaths of 60 000-000 juvenile fish. Between September and late winter river lamprey return to freshwater. Spawning occurs in the spring, from April to June and adults die after spawning. The length of adult life from the onset of metamorphosis until death following spawning is 2 yr. Pacific lamprey (Lampetra tridentata) begin metamorphosis in July and the known period of entry into salt water is from December until June. Feeding can commence in freshwater or salt water by mid-October. Pacific lamprey move into water deeper than 20–70 m and are present in all major fishing grounds off Canada's west coast. A relatively high incidence of lamprey attacks has been observed on sockeye and pink salmon that are aggregating in preparation to return to freshwater. The smallest mature or maturing pacific lamprey found in this study measured 16 cm and the largest measured 72 cm. Adults may spend [Formula: see text] in salt water before returning to freshwater from April to June and completing their upstream migrations by late September. Stocks that return in the spring exhibit exceptional migratory instincts often migrating considerable distances in freshwater to the uppermost regions of tributary streams before they spawn from April to July in the following year. After entry into freshwater and prior to spawning, adults shrink in length by approximately 20%. The average life span from the onset of metamorphosis until death following spawning probably is 5 yr. A nonanadromous form that appears to be a new species exists in lakes and attacks a large percentage of resident salmonids.Key words: Pacific lamprey, river lamprey, life history, fish parasites, Pacific fishes

THE THYROID GLAND IN RELATION TO THE SEAWARD MIGRATION OF PACIFIC SALMON

1950 ◽  
Vol 28d (3) ◽  
pp. 126-136 ◽  
Author(s):  
William S. Hoar ◽  
G. Mary Bell
Keyword(s):  
Fresh Water ◽  
Chum Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
River Estuary ◽  
Salt Balance ◽  
Thyroid Activity ◽  
Salmon Fry ◽  
Thyroid Glands ◽  
Seaward Migration

Histological examination of the thyroid glands from chum salmon fry taken in the river, estuary, or sea shows the organ to be in a quiescent condition at the time of migration. If, however, this species is retained in fresh water for two or three months the gland becomes extremely hyperplastic. The pink salmon thyroid behaves in essentially the same way as that of the chum, but migrating pink fry taken at great distances from the sea have active glands. The thyroids of yearling coho and sockeye moving into the sea display heightened activity. Thyroid activity is apparently greater in coho migrants taken later in the season from the headwaters of rivers. In part, the heightened thyroid activity seen in these migrating Pacific salmon is probably a spring-time seasonal change. It seems, however, to be more particularly related to the increased metabolic work of osmotic regulation and salt balance in a fish physiologically prepared for life in the sea. In general, this study suggests that the increased thyroid activity seen in young migrating salmonoids is largely due to increased demands for thyroid hormone in the metabolism of a fish no longer completely adjusted physiologically to fresh water.

Suspended Sediment Particles Inside Gills and Spleens of Juvenile Pacific Salmon (Oncorhynchus spp.)

1993 ◽  
Vol 50 (3) ◽  
pp. 586-590 ◽  
Author(s):  
Dennis W. Martens ◽  
James A. Servizi
Keyword(s):  
Suspended Sediment ◽  
Sockeye Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Pink Salmon ◽  
X Ray Diffraction ◽  
Mineral Particles ◽  
Juvenile Pacific Salmon ◽  
Sediment Particles ◽  
Laboratory Exposure

Intracellular sediment particles were observed in the gills of underyearling coho salmon (Oncorhynchus kisutch) and pink salmon (O. gorbuscha) following laboratory exposure to Fraser River sediment. Gills of underyearling sockeye salmon (O. nerka), chinook salmon (O. tshawytscha), and coho exposed to a natural suspended sediment in Cultus Lake hatchery water also contained intracellular mineral particles. Mineral particles were seen in both epithelial and underlying gill filamental cells, and it is believed that these particles were phagocytosed by the former. Intracellular sediment particles were also observed in spleens of some sediment-exposed fish. Electron microscopy was used to measure gill particle sizes and X-ray diffraction analysis to identify eight minerals and one metal in the gills of sockeye previously exposed to suspended sediment.

Rapid Learning of a Constant Course by Travelling Schools of Juvenile Pacific Salmon

1958 ◽  
Vol 15 (2) ◽  
pp. 251-274 ◽  
Author(s):  
William S. Hoar
Keyword(s):  
Pacific Salmon ◽  
Pink Salmon ◽  
Biological Significance ◽  
Reverse Direction ◽  
Latent Learning ◽  
Circular Channel ◽  
Compass Direction ◽  
Rapid Learning ◽  
Alternate Direction ◽  
Juvenile Pacific Salmon

Either individuals or schools of downstream-migrating chum, sockeye and pink salmon quickly establish a constant course in a circular channel. This clockwise or counter-clockwise course, once established, is not altered by a variety of disturbances including transfer to a channel of different size and shape or, in the case of the chum, removal from the apparatus for almost two days. The schools travel much more frequently in some particular area of a simple maze although, from time to time, they swim through all parts of it. The tendency to swim steadily forward in a winding maze seems to decline as the season of migration comes to an end. Fish trained to swim along one compass direction show no bias for this direction when given a choice of this or an alternate direction at right angles. Fish trained to reverse direction after a definite distance show a tendency to do this when given an opportunity to swim in a channel twice as long. The findings are discussed in relation to simple types of learning such as habituation, insight learning, latent learning and imprinting. The biological significance of the learning is considered in relation to the problem of migration.

scholarly journals Exceptional marine survival of pink salmon that entered the marine environment in 2003 suggests that farmed Atlantic salmon and Pacific salmon can coexist successfully in a marine ecosystem on the Pacific coast of Canada

2006 ◽  
Vol 63 (7) ◽  
pp. 1326-1337 ◽  
Author(s):  
Richard J. Beamish ◽  
Simon Jones ◽  
Chrys-Ellen Neville ◽  
Ruston Sweeting ◽  
Grace Karreman ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Pacific Salmon ◽  
Action Plan ◽  
Marine Ecosystem ◽  
Pink Salmon ◽  
Farmed Salmon ◽  
The Pacific ◽  
Marine Survival ◽  
Migration Corridor ◽  
Farmed Atlantic Salmon

Abstract Juvenile pink salmon that entered a marine ecosystem along the eastern margin of Queen Charlotte Strait in 2003 and returned as adults in 2004 had very high marine survival. The early seaward migration and midsummer rearing in 2003 were in an area containing 16 active Atlantic salmon farms. Two species of sea louse, Lepeophtheirus salmonis and Caligus clemensi, were commonly found on farmed salmon and juvenile Pacific salmon during the early rearing period of the pink salmon. Mobile L. salmonis and C. clemensi were most abundant on farmed Atlantic salmon from February to May and on pink salmon in June. Chalimus stages were the dominant stages on pink salmon to the end of May. Mobile stages of C. clemensi were the dominant stages and species of sea louse on farmed Atlantic salmon and pink salmon at about the same time in June. DNA studies showed that local juvenile pink salmon were in the area until August. The exceptional returns of the brood year suggest that pink salmon populations and farmed Atlantic salmon coexisted successfully during 2003 within an environment that included sea lice and farmed Atlantic salmon. The processes responsible for the high marine survival cannot be identified with certainty, but they could include increased freshwater discharge in 2003, which may have resulted in lower salinity less favourable to sea louse production, increased inflow of nutrient-rich water to the study area, and the introduction of a Provincial Action Plan that required mandatory louse monitoring and established a fallowed migration corridor for pink salmon.

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