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.

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.

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.

Spawning Behavior of Chum Salmon (Oncorhynchus keta) and Rainbow Trout (Salmo gairdneri)

1975 ◽  
Vol 32 (5) ◽  
pp. 633-642 ◽  
Author(s):  
A. F. Tautz ◽  
C. Groot
Keyword(s):  
Rainbow Trout ◽  
Chum Salmon ◽  
Nest Site ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Spawning Behavior ◽  
Current Pattern ◽  
Chum Salmon Oncorhynchus Keta ◽  
Nest Sites ◽  
Gravel Size

Detailed accounts of the spawning behavior of chum salmon (Oncorhynchus keta) and rainbow trout (Salmo gairdneri) in laboratory flumes are provided. The behavioral activities, quivering, probing, and crossing over increase in frequency as a function of time prior to spawning whereas digging remains constant or decreases slightly. Maps of digging locations and movie films suggest nest shape and current pattern are monitored by the female, allowing her to intensify her digging activity near the center of the nest. Probing appears to be a signal to the male indicating approach of oviposition and also provides information to the female regarding the shape and suitability of the nest site. The probing act is also used in the synchronization of the male and female spawning acts. Changes in velocity do not appear to markedly affect nest construction either in terms of number of digs to oviposition or in size of nest constructed. It is inferred that velocity and gravel size are important insofar as they influence the construction of a suitable nest depression. Nest sites would appear to be selected on the basis of acceleration of flow rather than velocity per se though high limits must obviously exist.

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

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.

Influence of Size Upon the Adaptation of Steelhead Trout (Salmo gairdneri) and Chum Salmon (Oncorhynchus keta) to Sea Water

1961 ◽  
Vol 18 (3) ◽  
pp. 401-415 ◽  
Author(s):  
Arthur H. Houston
Keyword(s):  
Chum Salmon ◽  
Sea Water ◽  
Water Salinity ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Electrolyte Balance ◽  
Steelhead Trout ◽  
Chum Salmon Oncorhynchus Keta ◽  
Salmonid Species ◽  
Juvenile Chum Salmon

Steelhead trout in the smolt phase of development adapted to sea water (salinity 22–24 parts per thousand) more rapidly and with less extensive departures from regulated conditions of water–electrolyte balance than did the larger post-smolts. By contrast, the extent and duration of the corresponding changes accompanying adaptation of juvenile chum salmon to sea water varied inversely with size. The data are discussed in relation to the distinction between smolting and non-smolting salmonid species.

Stream Temperatures and Inter-Annual Variability in the Emigration Timing of Coho Salmon (Oncorhynchus kisutch) Smolts and fry and Chum Salmon (O. Keta) Fry from Carnation Creek, British Columbia

1989 ◽  
Vol 46 (8) ◽  
pp. 1396-1405 ◽  
Author(s):  
L. Blair Holtby ◽  
Thomas E. McMahon ◽  
J. Charles Scrivener
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Oncorhynchus Keta ◽  
Windows Of Opportunity ◽  
Salmon Fry ◽  
Median Date ◽  
Wet Weight ◽  
Laboratory Models

Variability in average stream temperatures between peak spawning and fry emergence accounted for 82 and 77% of the variance in the median emigration date of fry of chum (Oncorhynchus keta) and coho salmon (O. kisutch) respectively over a 9 to 10-yr period. The modeled relationships were indistinguishable from laboratory models that predicted time to maximum alevin wet weight. Variability in stream temperatures during the spring accounted for 60% of the variability in the median date of coho smolt emigration. As stream temperatures increased, the predicted thermal summations required for emigration were nearly constant for coho salmon fry, increased moderately for chum salmon fry and increased strongly for coho salmon smolts The duration of the emigration period also differed between the groups: 50% of the chum salmon fry emigrated over a 1-wk period compared with a 2- to 3-wk period for coho salmon fry and smolts. We speculate that the emigration timing —temperature relationships and timing of adult spawning represent adaptations for synchronizing emigration with "windows of opportunity" in the ocean or stream. The windows are of different widths and levels of predictability for coho and chum salmon fry and coho salmon smolts.

Physiological Response of Juvenile Coho Salmon (Oncorhynchus kisutch) and Rainbow Trout (Salmo gairdneri) to Handling and Crowding Stress in Intensive Fish Culture

1976 ◽  
Vol 33 (12) ◽  
pp. 2699-2702 ◽  
Author(s):  
Gary A. Wedemeyer
Keyword(s):  
Rainbow Trout ◽  
Feeding Behavior ◽  
Coho Salmon ◽  
Physiological Stress ◽  
Oncorhynchus Kisutch ◽  
Fish Distribution ◽  
Salmo Gairdneri ◽  
Crowding Stress ◽  
Normal Feeding ◽  
Intensive Fish Culture

Moving 4–5-in. coho salmon (Oncorhynchus kisutch) held in soft (20 ppm CaCO3) water from the relatively light loading density of 0.5 lb/ft3 to 1, 2, or 4 lb/ft3 (density index, DI = 0.1, 0.2, 0.4, 0.8) caused significant stress as indicated by loss of feeding behavior, but only minimal physiological disturbances, as indicated by lack of hyperglycemia or hypochloremia. However, moving them to 6 or 12 lb/ft3 (DI = 1.2, 2.4) caused significant physiological stress which required at least a week for recovery. Smolting coho salmon were physiologically stressed by population densities of 1 lb/ft3 or more and a subclinical corynebacterial kidney infection was activated. Rainbow trout (Salmo gairdneri) (4–5 in.) were physiologically stressed when moved and held at 1 lb/ft3 or more but retained normal feeding behavior. This indicates that handling and crowding stress will be minimized in softwater areas if densities in fish distribution trucks or in ponds or raceways during disease treatments are held to 0.1–0.5 lb/gal.

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