5′-Nucleotidase of Testes of Immature Sockeye Salmon (Oncorhynchus nerka)

1970 ◽  
Vol 27 (11) ◽  
pp. 2003-2007
Author(s):  
Linda J. Gardner
Keyword(s):  
High Speed ◽  
Sockeye Salmon ◽  
Specific Activity ◽  
Soluble Fraction ◽  
Oncorhynchus Nerka ◽  
Single Peak ◽  
Nucleotidase Activity ◽  
Activity Curve

Fifty percent of the salmon 5′-nucleotidase is in the soluble fraction after high-speed centrifugation. A threefold purification on a Sephadex G-200 column gives a specific activity of 0.5 μmoles UMP hydrolyzed per hour per milligram of protein. The pH activity curve gives a single peak with an optimum at pH 9.0 MgCl2, CaCl2, and MnSO4 increase the activity whereas Zn acetate, Ni acetate, and CoSO4 inhibit the enzyme. EDTA, KF 2-mercaptoethanol, and dithiothreitol inhibit the nucleotidase activity. It is stable for up to 1 week at 0 C and up to 2 hr at 35 C, but activity decreases to 50% after 15 min at 50 C and no activity is left after 15 min at 60 C. The nucleotidase shows greatest activity towards 5′-nucleotides; 2′(3′) nucleotides and 5′-deoxynucleotides are hydrolyzed less effectively. Ribose-5-phosphate and p-nitrophenylphosphate are hydrolyzed, but no activity is exhibited against fructose-1-phosphate and α-glycerophosphate.

Respiratory Metabolism and Swimming Performance of the Squid, Loligo opalescens

1982 ◽  
Vol 39 (4) ◽  
pp. 580-587 ◽  
Author(s):  
R. K. O'Dor
Keyword(s):  
High Speed ◽  
Sockeye Salmon ◽  
Large Scale ◽  
Swimming Performance ◽  
Oncorhynchus Nerka ◽  
Oxygen Debt ◽  
Cost Of Transport ◽  
Loligo Opalescens ◽  
Single Jet ◽  
Low Efficiency

Maximum sustainable and burst speed, standard and active metabolic rates, and metabolic scope at temperatures from 7.5 to 17.5 °C were determined for the squid, Loligo opalescens, with a Brett tunnel respirometer. A comparison with sockeye salmon (Oncorhynchus nerka) of similar size at 15 °C indicates that squid have higher standard and active rates (254 and 862 mL O2∙kg−1∙h−1), but have sustainable speeds half those of salmon (0.36 m∙s−1). This confirms the low efficiency of jet-propelled swimming, and the resultant high cost of transport (12.5 J∙kg−1∙m−1; nearly 5 times that of salmon) raises interesting questions about how and why squid make large-scale vertical and horizontal migrations and the tactics they use to compete with fish that are both their predators and prey. Burst speeds after several maximal jets do not appear to be significantly greater than the peak speed after a single jet suggesting squid must depend primarily on maneuverability and high acceleration rather than high speed. A low capacity for accumulating an oxygen debt (73 mL O2∙kg−1) confirms predictions based on biochemical evidence. This debt is approximately equal to the energy needed to rephosphorylate muscle phosphagens.Key words: squid, swimming, oxygen consumption, oxygen debt, Loligo opalescens, metabolic rate, salmon, Oncorhynchus nerka

Influence of river speed on path selection by migrating adult sockeye salmon (Oncorhynchus nerka)

2004 ◽  
Vol 61 (6) ◽  
pp. 905-912 ◽  
Author(s):  
Emily M Standen ◽  
Scott G Hinch ◽  
Peter S Rand
Keyword(s):  
Swimming Speed ◽  
High Speed ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Path Selection ◽  
Current Speed ◽  
Current Profile ◽  
Migration Strategy ◽  
Ground Speed

We applied stereovideographic techniques to investigate path selection, ground speed, and swimming speed in adult sockeye salmon (Oncorhynchus nerka) ascending the Seton River, British Columbia. We tracked three-dimensional trajectories of salmon through 10 reaches and characterized the current profile at each site. At sites with relatively slow currents, the encountered river current speeds along the fish's trajectory were significantly lower than the mean current speed of the site. However, at higher current speed sites, fish experienced current speeds at or above the average current speed of the site and increased their ground speed through these sites. Observed in situ swimming speeds were 1.4–76.0 times greater than swimming speeds expected based on tailbeat frequency – swimming speed predictive relationships established in flume studies. We conclude that (i) at sites with relatively slow or moderate current speeds, fish minimize exposure to high-speed currents to minimize energy expenditure, (ii) at sites with high-speed currents, fish may change their migration strategy, minimizing time spent searching for low current speed pathways and increasing their ground speed to expedite passage, and (iii) laboratory-derived predictive equations may only be appropriate for predicting in situ swimming costs at sites with moderate and linearly flowing currents.

Resumption of anadromy or straying? Origins of Sockeye Salmon Oncorhynchus nerka in the Elwha River

2021 ◽  
Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Elwha River

Alternative Recruitment Models of Adams River Sockeye Salmon, Oncorhynchus nerka

1987 ◽  
Vol 44 (9) ◽  
pp. 1551-1561 ◽  
Author(s):  
Jeremy S. Collie ◽  
Carl J. Walters
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Status Quo ◽  
Management Policy ◽  
Best Management ◽  
Interaction Terms ◽  
Ricker Model ◽  
The Status ◽  
Stock Recruitment ◽  
High Yields

Despite evidence of depensatory interactions among year-classes of Adams River sockeye salmon (Oncorhynchus nerka), the best management policy is one of equal escapement for all year-classes. We fit alternative models (Ricker model and Larkin model) to 32 yr of stock–recruitment data and checked, using simulation tests, that the significant interaction terms in the Larkin model are not caused by biases in estimating the parameters. We identified a parameter set (Rationalizer model) for which the status quo cyclic escapement policy is optimal, but this set fits the observed data very poorly. Thus it is quite unlikely that the Rationalizer model is correct or that the status quo escapement policy is optimal. Using the fitted stock–recruitment parameters, we simulated the sockeye population under several management policies. The escapement policy optimal under the Ricker model is best overall because of the high yields if it should be correct. If the three stock–recruitment models are equally likely to be correct, the simulations predict that adopting a constant-escapement policy would increase long-term yield 30% over the current policy and that an additional 15% increase in yield could be obtained if the policy were actively adaptive.

Reduced growth in wild juvenile sockeye salmon Oncorhynchus nerka infected with sea lice

2017 ◽  
Vol 91 (1) ◽  
pp. 41-57 ◽  
Author(s):  
S. C. Godwin ◽  
L. M. Dill ◽  
M. Krkošek ◽  
M. H. H. Price ◽  
J. D. Reynolds
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Sea Lice

Validation of daily increments and a marine-entry check in the otoliths of sockeye salmon Oncorhynchus nerka post-smolts

2015 ◽  
Vol 87 (1) ◽  
pp. 169-178 ◽  
Author(s):  
C. Freshwater ◽  
M. Trudel ◽  
T. D. Beacham ◽  
C.-E. Neville ◽  
S. Tucker ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Daily Increments

Biochemical Studies on Sockeye Salmon During Spawning Migration: XI. The Free Histidine Content of the Tissues

1960 ◽  
Vol 17 (3) ◽  
pp. 347-351 ◽  
Author(s):  
J. D. Wood ◽  
D. W. Duncan ◽  
M. Jackson
Keyword(s):  
Amino Acid ◽  
Sockeye Salmon ◽  
Alimentary Tract ◽  
Oncorhynchus Nerka ◽  
The Other ◽  
Spawning Migration ◽  
Fraser River ◽  
Initial Value ◽  
Spawning Grounds ◽  
Biochemical Studies

During the first 250 miles (400 km) of spawning migration of Fraser River sockeye salmon (Oncorhynchus nerka) the free histidine content of the muscle, alimentary tract, and head+skin+bones+tail decreased to a small fraction of the initial value. A further decrease occurred in the levels of this amino acid in the alimentary tract during the subsequent 415-mile (657-km) migration to the spawning grounds, no change being observed with the other tissues. Comparatively small changes in free histidine were found with heart, spleen, liver, kidney and gonads during migration.

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