Treatments Before Frozen Storage Affecting Thaw Drip Formation in Pacific Salmon

1977 ◽  
Vol 34 (9) ◽  
pp. 1431-1435 ◽  
Author(s):  
E. Bilinski ◽  
R. E. E. Jonas ◽  
Y. C. Lau ◽  
G. Gibbard
Keyword(s):  
Key Words ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Frozen Storage ◽  
Freezing Rate ◽  
Slow Freezing ◽  
Oncorhynchus Keta ◽  
Temperature Range ◽  
Chum Salmon Oncorhynchus Keta

Freshly caught chum salmon, Oncorhynchus keta, were stored in ice or refrigerated seawater for 0.3 and 10 days and were then gutted and frozen at two different rates (1 or 14.5 h through the temperature range of 0 to −5 °C). The amount of thaw drip (TD) was determined in steaks following 1.5, 4, 8, and 12 mo of storage at −28 °C. A significant increase in TD occurred with the slow freezing rate or with a delay before freezing. These effects were not suppressed by a prolonged frozen storage, which also produced an increase in TD. There was no marked difference between fish held in ice and refrigerated seawater before freezing. Similar results were obtained with coho salmon, O. kisutch, frozen without prior chill stowage. Key words: Pacific salmon, thaw drip, chill stowage, freezing rates Oncorhynchus keta, O. kisutch

Swimming speeds and buoyancy compensation of migrating adult chum salmon Oncorhynchus keta revealed by speed/depth/acceleration data logger

2001 ◽  
Vol 204 (22) ◽  
pp. 3895-3904 ◽  
Author(s):  
Hideji Tanaka ◽  
Yasuaki Takagi ◽  
Yasuhiko Naito
Keyword(s):  
Chum Salmon ◽  
Pacific Salmon ◽  
Release Site ◽  
Oncorhynchus Keta ◽  
Horizontal Distance ◽  
Data Logger ◽  
Body Angle ◽  
Chum Salmon Oncorhynchus Keta ◽  
Acceleration Data ◽  
Free Ranging

SUMMARY Although the homing migration of Pacific salmon is well documented, the swimming behaviour of the returning salmon has been poorly described, principally as a result of the difficulties encountered in monitoring salmon behaviour in the sea. The present study describes the use of a recently developed electronic data logger to obtain simultaneous recordings of the swimming speed, depth, fin-beating activity and body angle of free-ranging chum salmon Oncorhynchus keta during their homing migration in coastal waters. Chum salmon migrated horizontally at speeds of 1.5–3.0 km h–1. The gross horizontal distance salmon moved during total recording periods were 1.24- to 19.0-fold greater than the net distance from the release site to the retrieval points. It is suggested that homing salmon did not drift passively but swam actively to the spawning grounds. Salmon preferred the surface water, but also made frequent vertical migrations. The travelled depth of each salmon ranged from 0.36 to 0.64 km per hour. Salmon descended at faster rates and steeper angles than they ascended. Both tailbeat frequency and tail thrust were higher during the ascent than the descent phase. These results suggest that chum salmon spent more energy during the ascent than the descent phase. Profiles of descent rate assumed an arched shape with respect to a change in hydrostatic pressure, while ascent rate increased with decreasing depth. High tailbeat frequencies were found during the course of ascent, which suggests that the salmon did not regulate the volume of air in the swim bladder during short-term vertical migrations.

Influence of the Abundance, Size, and Yolk Reserves of Juvenile Chum Salmon (Oncorhynchus keta) on Predation by Freshwater Fishes in a Small Coastal Stream

1987 ◽  
Vol 44 (2) ◽  
pp. 236-243 ◽  
Author(s):  
Kurt L. Fresh ◽  
Steven L. Schroder
Keyword(s):  
Chum Salmon ◽  
Coho Salmon ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Predator Prey ◽  
Chum Salmon Oncorhynchus Keta ◽  
Salmon Fry ◽  
Juvenile Chum Salmon ◽  
Controlled Flow ◽  
The Relationship

Predator–prey interactions between juvenile chum salmon (Oncorhynchus keta) and piscivores were studied in a small coastal stream and in sections of a controlled-flow channel. The predators were primarily large [Formula: see text] rainbow trout (Salmo gairdneri) and large [Formula: see text] coho salmon (O. kisutch). The relationship between chum salmon fry abundance and the quantity consumed by predators suggested a type II functional response. Neither prey size nor prey abundance influenced predation, but predators did select fry with relatively high yolk reserves. Our results suggest that the numbers of juvenile chum salmon needed to satiate predators and to enhance fry survival are attainable by enhancement projects located on smaller rivers and streams.

On the structure and enzymatic degradation of the external membrane of the salmon egg

1969 ◽  
Vol 47 (1) ◽  
pp. 146-148 ◽  
Author(s):  
Gordon R. Bell ◽  
Gary E. Hoskins ◽  
John W. Bagshaw
Keyword(s):  
Metal Ions ◽  
Enzymatic Degradation ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Hatching Enzyme ◽  
Chum Salmon Oncorhynchus Keta ◽  
Optimum Ph

The radiate membrane ("capsule") of chum salmon (Oncorhynchus keta) eggs has integrated with it another, outermost, non-chitinous membrane which prevents the digestion of the radiate membrane by "hatching enzyme" of chum salmon or by pronase applied externally but not internally. Crude chum salmon hatching enzyme(s) has an optimum pH of 7.5–8.0 for the release of soluble peptides from the radiate membrane, requires metal ions for activity, and can also decompose the radiate membranes of coho salmon (Oncorhynchus kisutch) and steelhead (Salmo gairdneri) eggs.

Rule of age and size at maturity of chum salmon (Oncorhynchus keta): implications of recent trends among Oncorhynchus spp.

2005 ◽  
Vol 62 (12) ◽  
pp. 2752-2759 ◽  
Author(s):  
Kentaro Morita ◽  
Shoko H Morita ◽  
Masa-aki Fukuwaka ◽  
Hiroyuki Matsuda
Keyword(s):  
Growth Rate ◽  
Chum Salmon ◽  
Environmental Changes ◽  
Pacific Salmon ◽  
Oncorhynchus Keta ◽  
Size At Maturity ◽  
Chum Salmon Oncorhynchus Keta ◽  
Realistic Modeling ◽  
Recent Trends ◽  
Slow Growing

In the last quarter of the 20th century, the size at maturity of many North Pacific salmon (Oncorhynchus spp.) populations decreased. During this same period, the age at maturity increased, implying that the growth rate of Pacific salmon decreased, probably owing to environmental changes. To elucidate these trends, we identified the rule of age and size at maturity of Japanese chum salmon (Oncorhynchus keta), which was that slow-growing salmon initiated maturation at an older age and smaller size than did fast-growing salmon. We then simulated the potential modification of age and size at maturity in response to changing growth rate using a size-structured model with age- and size-specific maturation rates. This showed that reducing the growth rate without assuming a genetic change was sufficient for realistic modeling of recent changes. In addition, the observed rule of age and size at maturity was consistent with the optimal age and size at maturity in terms of maximizing the fitness. Our results attributed the recent trends in chum salmon's increasing age and decreasing size at maturity to an adaptive phenotypic response to a reduced growth rate.

Ceratomyxa shasta (Myxosporida) Disease in Chum Salmon (Oncorhynchus keta) in British Columbia

1975 ◽  
Vol 32 (9) ◽  
pp. 1640-1643 ◽  
Author(s):  
L. Margolis ◽  
T. P. T. Evelyn
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Host Record ◽  
Oncorhynchus Keta ◽  
New Host ◽  
Chum Salmon Oncorhynchus Keta ◽  
New Host Record ◽  
Natural Range ◽  
Juvenile Chum Salmon

Infections with the myxosporidan Ceratomyxa shasta Noble, 1950 were confirmed in four juvenile chum salmon (Oncorhynchus keta) caught at sea near Nanaimo in 1965 and 1968. These cases represent a new host record for C. shasta and a northward extension of the parasite’s known natural range. Ceratomyxosis was also presumptively diagnosed in a coho salmon (Oncorhynchus kisutch) in British Columbia.

Effect of egg size on incubation time and alevin and fry size in chum salmon (Oncorhynchus keta) and coho salmon (Oncorhynchus kisutch)

1985 ◽  
Vol 63 (4) ◽  
pp. 847-850 ◽  
Author(s):  
T. D. Beacham ◽  
F. C. Withler ◽  
R. B. Morley
Keyword(s):  
Egg Size ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Oncorhynchus Keta ◽  
Free Swimming ◽  
Chum Salmon Oncorhynchus Keta ◽  
Hatching Time ◽  
Significant Difference ◽  
Yolk Absorption

Variability in hatching time, time of exogenous yolk absorption ("button up") of alevins, alevin size, and fry size was investigated with respect to initial egg size for chum salmon (Oncorhynchus keta) and coho salmon (Oncorhynchus kisutch). There was no significant difference with respect to egg size in hatching time of the alevins (stage between hatching and emergence from the redd) or time of exogenous yolk absorption for either species. For both species, alevins hatching from large eggs were longer and had greater amounts of yolk than those hatching from small eggs. Tissue weights of the alevins were not different. The differences in size between these two groups of alevins were maintained throughout the alevin stage and were greater at exogenous yolk absorption than at hatching. Fry (newly emerged, free-swimming young) derived from large eggs had greater tissue weight at exogenous yolk absorption than those derived from small eggs.

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