Glycogen and Lactic Acid Concentrations in Atlantic Cod (Gadus morhua) in Relation to Exercise

1968 ◽  
Vol 25 (5) ◽  
pp. 837-851 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Lactic Acid ◽  
Swimming Speed ◽  
Muscle Glycogen ◽  
Similar Pattern ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Recovery Period ◽  
Strenuous Exercise ◽  
Before And After ◽  
Exercise Muscle

In Atlantic cod, muscle glycogen was reduced by about 50% at moderate swimming speeds and over 80% at higher speeds. Muscle glycogen for a given swimming speed was generally lower after 30 min exercise than after 15 min exercise. During the 8-hr period after strenuous exercise, muscle glycogen increased but remained well below the level for unexercised fish.At moderate swimming speeds, fish exhibited comparatively small amounts of muscle and blood lactic acid. At higher swimming speeds, fish accumulated significantly larger quantities of lactic acid in the muscle and blood. During the recovery period after strenuous exercise, muscle and blood lactic acid increased precipitously. Muscle lactic acid remained high for 1 hr after exercise and then decreased in 8 hr to levels similar to those of unexercised cod. Blood lactic acid followed a similar pattern except that it continued to increase for 1.5 hr after exercise.Serial samples of blood taken before and after 30 min strenuous exercise showed marked differences in lactic acid among individuals. Blood lactic acid usually continued to increase for 30–60 min after exercise, and decreased to the level for unexercised fish about 24 hr after exercise.No mortalities attributable to muscular fatigue occurred among cod.

Effect of carbohydrate ingestion on exercise metabolism

1988 ◽  
Vol 65 (4) ◽  
pp. 1553-1555 ◽  
Author(s):  
M. Hargreaves ◽  
C. A. Briggs
Keyword(s):  
Muscle Glycogen ◽  
Venous Blood ◽  
Cycle Ergometer ◽  
Strenuous Exercise ◽  
Carbohydrate Ingestion ◽  
Ergometer Exercise ◽  
Glucose Polymer ◽  
Before And After ◽  
Plasma Insulin Levels ◽  
Glycogen Utilization

Five male cyclists were studied during 2 h of cycle ergometer exercise (70% VO2 max) on two occasions to examine the effect of carbohydrate ingestion on muscle glycogen utilization. In the experimental trial (CHO) subjects ingested 250 ml of a glucose polymer solution containing 30 g of carbohydrate at 0, 30, 60, and 90 min of exercise; in the control trial (CON) they received an equal volume of a sweet placebo. No differences between trials were seen in O2 uptake or heart rate during exercise. Venous blood glucose was similar before exercise in both trials, but, on average, was higher during exercise in CHO [5.2 +/- 0.2 (SE) mmol/l] compared with CON (4.8 +/- 0.1, P less than 0.05). Plasma insulin levels were similar in both trials. Muscle glycogen levels were also similar in CHO and CON both before and after exercise; accordingly, there was no difference between trials in the amount of glycogen used during the 2 h of exercise (CHO = 62.8 +/- 10.1 mmol/kg wet wt, CON = 56.9 +/- 10.1). The results of this study indicate that carbohydrate ingestion does not influence the utilization of muscle glycogen during prolonged strenuous exercise.

The effect of magnesium oxide supplementation on muscle glycogen metabolism before and after exercise and at slaughter in sheep

2001 ◽  
Vol 52 (7) ◽  
pp. 723 ◽  
Author(s):  
G. E. Gardner ◽  
R. H. Jacob ◽  
D. W. Pethick
Keyword(s):  
Magnesium Oxide ◽  
Muscle Glycogen ◽  
Glycogen Metabolism ◽  
Post Exercise ◽  
Exercise Regimen ◽  
Before And After ◽  
Series Of Experiments ◽  
Glycogen Repletion ◽  
Exercise Muscle ◽  
Muscle Biopsies

This study was a series of experiments designed to test the influence of supplemental magnesium oxide (MgO) on muscle glycogen concentration in sheep exposed to stress (exercise) and the commercial slaughter process, and to test the effectiveness of this supplement in the commercial scenario. In Expt 1, Merino wethers maintained on a mixed ration (metabolisable energy 11 MJ/kg and crude protein 16.3% in DM) were supplemented with MgO at the rate of 0%, 0.5%, or 1% of their ration for 10 days prior to a single bout of exercise and for 10 days prior to slaughter at a commercial abattoir. The exercise regimen consisted of 4 intervals of 15 min, with muscle biopsies taken by biopsy drill from the m. semimembranosis (SM) and m. semitendinosis (ST) pre-exercise and immediately post-exercise, and at 36 and 72 h post-exercise. Muscle biopsies were also taken 1 week prior to slaughter from the SM and ST, with further samples taken approximately 30 min post-slaughter. Ultimate pH (pHu) of the SM, ST, and m. longissimus dorsi (LD) was measured 48 h after slaughter. Sheep supplemented with MgO lost less muscle glycogen in the ST during exercise, and repleted more muscle glycogen in the SM during the post-exercise repletion phase, than unsupplemented sheep. The supplemented animals also had higher muscle glycogen concentrations in the ST at slaughter. In Expt 2, MgO was administered to Merino wether lambs for 4 days prior to slaughter in the form of a water-borne slurry at a rate equivalent to 1% of their ration. This treatment resulted in significantly reduced muscle glycogen concentrations in both the SM and ST at slaughter. In Expts 3–5, MgO was used as an ‘in-feed’ supplement in the commercial scenario. In each case, slaughter-weight Merino lambs were supplemented with MgO at the rate of 1% of their ration for 4 days prior to commercial slaughter. Positive responses were seen in 2 of the 3 experiments, with increased glycogen concentrations and a reduced pHu. The animals that demonstrated no response to MgO had the lowest pHu after slaughter, suggesting a minimal stress load, thus providing very little scope for an effect of the MgO supplement. We conclude that MgO can reduce the effects of exercise, leading to a subsequent reduction in glycogen loss, and an increase in the rate of glycogen repletion in skeletal muscle following exercise. The results support MgO supplementation as a viable option for reducing the stress associated with commercial slaughter.

Evidence for the Assumption of Independence between Gastric Emptying Rate and Swimming Activity Using Atlantic Cod, Gadus morhua

1977 ◽  
Vol 34 (12) ◽  
pp. 2411-2413 ◽  
Author(s):  
A. V. Tyler
Keyword(s):  
Gastric Emptying ◽  
Key Words ◽  
Swimming Speed ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Swimming Activity ◽  
Rate Data ◽  
Gastric Emptying Rate ◽  
Digestion Rate ◽  
Sufficient Magnitude

Juvenile Atlantic cod, Gadus morhua, were forced to swim at speeds of 0.07, 0.6, and 1.2 body lengths/s after eating measured quantities of food. Higher speeds could not be maintained for more than 2 days. Only the highest speed caused a decrease in gastric emptying rate, but the decrease was not of sufficient magnitude to interfere with ration estimates based on digestion rate data. Key words: feeding, swimming speed, digestion rate

Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s

2005 ◽  
Vol 62 (7) ◽  
pp. 1453-1473 ◽  
Author(s):  
Alida Bundy
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Trophic Levels ◽  
Total Biomass ◽  
Scotian Shelf ◽  
Mass Balance Models ◽  
Key Species ◽  
Before And After ◽  
Species Groups ◽  
System Properties

The fishery-induced collapse of the Atlantic cod (Gadus morhua) stock on the eastern Scotian Shelf has altered the species composition of this ecosystem. Ecopath mass-balance models of the ecosystem before and after the collapse were developed to explore how the structure, function, and key species of the ecosystem had changed. For the first time, an analysis of uncertainty was conducted to examine the effects of the uncertainty on model estimates. A comparison of the two Ecopath models indicated that although total productivity and total biomass of the ecosystem remained similar, there were changes in predator structure, trophic structure, and energy flow, many of which were robust to uncertainty. Biomass has significantly increased at trophic levels 3 and 4, and the composition of these trophic levels has changed as a result of the mean increase in trophic level of many species-groups. Piscivory has increased, presumably because of the high abundance of small pelagic fish, and the ratio of pelagic feeders to demersal feeders has increased from 0.3 to 3.0. Thus, the ecosystem has changed from a demersal-feeder-dominated system to a pelagic-feeder-dominated system. Although uncertainty remains concerning some model estimates, the ecosystem has been profoundly altered and exhibits classic symptoms of "fishing down the food web". However, overall system properties were generally conserved.

Blood Lactate Levels in Free-Swimming Rainbow Trout (Salmo gairdneri) Before and After Strenuous Exercise Resulting in Fatigue

1976 ◽  
Vol 33 (1) ◽  
pp. 173-176 ◽  
Author(s):  
William R. Driedzic ◽  
Joe W. Kiceniuk
Keyword(s):  
Rainbow Trout ◽  
Blood Lactate ◽  
White Muscle ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Strenuous Exercise ◽  
Salmo Gairdneri ◽  
Before And After ◽  
Lactate Levels

Rainbow trout (Salmo gairdneri) were exercised to fatigue in a series of 60-min stepwise increasing velocity increments. There was no increase in blood lactate concentration, serially sampled during swimming by means of indwelling dorsal and ventral aortic catheters, at velocities as high as 93% of critical velocity of individuals. The data show that under these conditions the rate of production of lactate by white muscle, at less than critical velocities, is minimal or that the rate of elimination of lactate from white muscle is equal to its rate of utilization elsewhere. Immediately following fatigue blood lactate level increases rapidly. During the recovery period there appears to be a net uptake of lactate by the gills.

Factors affecting the swimming endurance and catchability of Atlantic cod (Gadus morhua)

2000 ◽  
Vol 57 (6) ◽  
pp. 1200-1207 ◽  
Author(s):  
Paul D Winger ◽  
Pingguo He ◽  
Stephen J Walsh
Keyword(s):  
Swimming Speed ◽  
Newfoundland And Labrador ◽  
Gadus Morhua ◽  
Failure Time ◽  
Atlantic Cod ◽  
Fish Length ◽  
Time Analysis ◽  
Factors Affecting ◽  
Highly Sensitive ◽  
Swimming Endurance

The swimming endurance of Atlantic cod (Gadus morhua), native to the cold waters off the east coast of Newfoundland and Labrador, was investigated under laboratory conditions. Using a swimming flume, endurance was tested at swimming speeds ranging from 0.6 to 1.3 m·s-1 using water temperatures from 0.0 to 9.8°C ( mean = 3.2°C, SD = 2.8) and fish lengths from 41.0 to 86.0 cm ( mean = 57.8 cm, SD = 10.5). The results revealed that swimming speed was the only significant factor affecting the endurance of cod. The maximum sustained swimming speed (Ums) was predicted to be 0.66 m·s-1. Statistical analysis of the data was conducted using failure time analysis. The hazard, or risk of exhaustion, was found to increase rapidly with increasing swimming speed, i.e., there was a decrease in the probability of cod achieving a given swimming endurance. Probability curves for the endurance of cod were calculated for different swimming speeds. The findings suggest that the catching efficiency of commercially targeted cod (>41.0 cm) by otter trawls may be highly sensitive to changes in towing speed while being independent of both fish length and water temperature.

Alterations in Glycogen, Glucose and Lactate in Rainbow and Kamloops Trout, Salmo gairdneri, Following Muscular Activity

1960 ◽  
Vol 17 (4) ◽  
pp. 487-500 ◽  
Author(s):  
Edgar C. Black ◽  
Anne C. Robertson ◽  
Arthur R. Hanslip ◽  
Wing-Gay Chiu
Keyword(s):  
Blood Lactate ◽  
Muscle Glycogen ◽  
Muscular Activity ◽  
Liver Glycogen ◽  
Strenuous Exercise ◽  
Salmo Gairdneri ◽  
Moderate Activity ◽  
Starvation Period ◽  
Exercise Muscle ◽  
Lactate Levels

Rainbow trout [Formula: see text] years old (fall spawners) raised in the hatchery at Summerland, B.C., and 2-year-old mature spawning Kamloops trout (spring spawners) captured from Lake Okanagan, were subjected to 15 minutes strenuous exercise. Muscle glycogen was depleted in both groups. Following 30 minutes of moderate activity, muscle glycogen remained high in the [Formula: see text]-year-old trout. Liver glycogen levels were not significantly lowered during either strenuous or moderate exercise. Blood lactate levels were markedly elevated during 15 min of strenuous exercise and continued to rise for 2 hours of post-exercise recovery in both groups of fish. In the [Formula: see text]-year-old trout, blood lactate declined to resting levels at about the 8th hour of recovery, and was increased 3-fold following 30 min of moderate activity. Blood glucose and hemoglobin were not significantly altered during either strenuous or moderate activity.In the [Formula: see text]-year-old trout, starvation of up to 7 days duration resulted in a marked depletion of liver glycogen. There was little change in muscle glycogen, blood lactate, glucose or hemoglobin, regardless of whether or not the fish had been exercised at the beginning of the starvation period. Feeding during the period of recovery from 15 min of strenuous exercise resulted in increases in both muscle and liver glycogen levels.

Potential methods for measuring the activity patterns and energy use of Atlantic cod (Gadus morhua)

2009 ◽  
Vol 66 (7) ◽  
pp. 1095-1106 ◽  
Author(s):  
Matthew J. Gollock ◽  
Kristopher J. Hunter ◽  
Douglas A. Syme ◽  
Marcus Freeman ◽  
R. Scott McKinley ◽  
...  
Keyword(s):  
Swimming Speed ◽  
Gadus Morhua ◽  
Energy Use ◽  
Atlantic Cod ◽  
Activity Patterns ◽  
Strong Relationship ◽  
Marine Species ◽  
Free Swimming ◽  
Cost Of Transport ◽  
Wide Range

As there are no commercially available acoustic telemetry devices for quantifying the swimming activity and activity-related metabolic expenditures of a wide range of marine species, we (i) examined the suitability of three methods (electromyography; sonomicrometry; and tail differential pressure tags (DPT)) for measuring the swimming speed of Atlantic cod ( Gadus morhua ), and indirectly, metabolic rate (MO2) and (ii) measured the activity pattern of free-swimming cod carrying the DPT. All three methods yielded significant relationships with swim speed during a critical swimming speed (Ucrit) test. However, only the DPT was able to discern between swimming speed differences of 0.1 body lengths (BL)·s–1 and provide a strong relationship with MO2. Further, we found that free-swimming cod fitted with the DPT swam at an average speed of 0.33 BL·s–1, the speed previously reported to result in minimal cost of transport for this species. While the DPT has considerable potential for assessing the bioenergetics of marine fishes, the swimming economy of tagged Atlantic cod was lower above 0.4 BL·s–1 as compared with untagged fish, and Ucrit was reduced by 25%. These latter effects are likely related to the tag’s present size (39 g) and design.

Sign in / Sign up

Export Citation Format

Share Document