Physiology and performance of wild and domestic strains of diploid and triploid rainbow trout (Oncorhynchus mykiss) in response to environmental challenges

2015 ◽  
Vol 72 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Mark A. Scott ◽  
Rashpal S. Dhillon ◽  
Patricia M. Schulte ◽  
Jeffrey G. Richards
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Swimming Speed ◽  
Hypoxia Tolerance ◽  
Consistent Difference ◽  
Critical Swimming Speed ◽  
Environmental Challenges ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Wild Strains

To determine the factors that may contribute to the poor survival of triploid (3n) rainbow trout (Oncorhynchus mykiss) in lake stocking programs, we compared the physiology and responses to environmental challenges of four wild strains and one domestic strain of diploid (2n) and 3n juvenile rainbow trout. Over four successive years, wild trout were caught from nature, spawned, and progeny were reared in a hatchery along with hatchery-bred domestic trout. Offspring of each strain were raised for up to 12 months as both 2n and 3n, and growth rate, critical swimming speed, routine oxygen consumption rate, critical oxygen tensions, thermal tolerance, and hypoxia tolerance were assessed in a laboratory setting. Cohorts of the 2008, 2009, and 2010 wild strains were also stocked into two experimental lakes and recaptured as adults using traps and fyke nets in 2011 for laboratory analysis. In the juvenile trout, the only measure of performance to show a consistent difference between 2n and 3n individuals across all strains was hypoxia tolerance, where 3n trout had a shorter time to loss of equilibrium (LOE) at 16 Torr than their 2n counterparts, but this effect was not seen in adult, lake-reared trout. Strain had a significant effect on specific growth rate, critical swimming speed (Ucrit), and time to LOE in hypoxia, although the effects of strain on these variables was not consistent from year to year. Overall, this study suggests that poorer hypoxia tolerance in 3n trout compared with 2n trout may be a contributing factor to the higher lake stocking mortalities in 3n trout.

Effect of recovery parameters on critical swimming speed of juvenile rainbow trout (Oncorhynchus mykiss)

1997 ◽  
Vol 75 (10) ◽  
pp. 1724-1727 ◽  
Author(s):  
S. Peake ◽  
R. S. McKinley ◽  
C. Barth
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Swimming Speed ◽  
Recovery Phase ◽  
Physiological Status ◽  
Critical Swimming Speed ◽  
Handling Stress ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Recovery Times

Critical swimming speed (Ucrit) is commonly measured to evaluate the influence of particular parameters on the swimming ability and physiological status of fish. Prior to experiments, fish are often forced to swim at low speed for a period of time to allow them to recover from handling stress. In the past, recovery times and speeds have varied from study to study but their possible effects on Ucrit have not been thoroughly examined. Therefore, hatchery-reared juvenile rainbow trout (Oncorhynchus mykiss) were forced to swim at a velocity of 26.5 cm/s for 0, 0.5, 1, 2, 4, 8, or 16 h or at a velocity of 0, 17.0, 21.8, 26.5, 36.0, or 45.5 cm/s for 0.5 h prior to being subjected to the Ucrit protocol (5-min intervals and 2.5 cm/s increments were used). Fish were tested at 6 and 18 °C. Mean Ucrit values were independent of recovery time and speed at both temperatures, suggesting that the recovery phase of the protocol may not be required and that inconsistencies in Ucrit values among studies are probably not attributable to differences in recovery parameters used.

Composition and Mechanics of Routine Swimming of Rainbow Trout, Oncorhynchus mykiss

1991 ◽  
Vol 48 (4) ◽  
pp. 583-590 ◽  
Author(s):  
Paul W. Webb
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Correction Factor ◽  
Swimming Speed ◽  
Angular Acceleration ◽  
Force Balance ◽  
Whole Body ◽  
Strongly Correlated ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Tail Beat

Routine swimming encompasses all volitional motions of fish. It is usually assumed to be quasi-steady, i.e. routine swimming is mechanically equivalent to steady swimming. Routine swimming of rainbow trout, Oncorhynchus mykiss, was dominated by unsteady motions of linear and centripetal (angular) acceleration. Constant-speed swimming was rare. Mean speeds and acceleration rates were small. Tail-beat frequencies were nevertheless strongly correlated with mean swimming speed, but increased more rapidly with increasing speed in routine swimming than in steady swimming. Tail-beat amplitudes and propulsive wavelengths were similar to values seen in steady swimming. The composition of routine swimming and analysis of the force balance showed that routine swimming was not quasi-steady. Therefore, forces and rates of working should be estimated from a complete description of whole-body deformation. This is impractical. Drag dominated resistance in routine swimming, such that average thrust (= resistance) may be computed from mean speed and/or averaged kinematic variables for the trailing edge with a correction factor of approximately 3. Analysis of routine swimming may permit comparisons among a wider range of vertebrates than possible with commonly used methods.

Individual variation and interrelationships between swimming performance, growth rate, and feeding in juvenile rainbow trout (Oncorhynchus mykiss)

1998 ◽  
Vol 55 (7) ◽  
pp. 1583-1590 ◽  
Author(s):  
T Ryan Gregory ◽  
Chris M Wood
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Plasma Cortisol ◽  
Positive Relationship ◽  
Swimming Performance ◽  
Individual Performance ◽  
Significant Positive Relationship ◽  
Juvenile Rainbow Trout ◽  
Rainbow Trout Oncorhynchus Mykiss

Variation among individuals in specific growth rate (SGR), feeding, and two measures of swimming performance and their possible interrelationships were investigated in juvenile rainbow trout (Oncorhynchus mykiss) kept in groups on either satiation or half-satiation rations. Maximum sustainable velocity (Ucrit) was measured as an index of aerobic swimming performance and stamina (fatigue time in a fixed-velocity test at 6 body lengths ·s-1) as an index of anaerobic performance. Individual performance in both of these tests was found to be significantly repeatable. Trout fed on half-satiation ration exhibited significantly lower mean values of SGR and body size and higher levels of aggression-related fin damage, but no significant differences in stamina, relative or absolute Ucrit, glycogen content, or plasma cortisol. However, in these fish, there was a significant negative relationship between SGR and relative Ucrit, a significant positive relationship between SGR and stamina, and a significant positive relationship between SGR and total daily meal. None of these relationships were seen in fish fed to satiation. Plasma cortisol and tissue glycogen stores were not related to SGR. These results indicate that under the intensified competition of restricted ration, there are trade-offs between growth, feeding, and different types of swimming performance.

RNA/DNA ratios in white muscle as estimates of growth in rainbow trout held at different temperatures

1990 ◽  
Vol 68 (7) ◽  
pp. 1494-1498 ◽  
Author(s):  
Moira M. Ferguson ◽  
Roy G. Danzmann
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
White Muscle ◽  
Specific Growth ◽  
Fish Size ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Different Temperatures ◽  
Specific Growth Rates ◽  
Rna And Dna

The concentrations of RNA, DNA, and protein in white muscle from 240 uniquely tagged rainbow trout (Oncorhynchus mykiss) held at three temperatures (5, 8 (control), and 11 °C) were measured. Both RNA and RNA/DNA ratios were better predictors of recent length- and weight-specific growth rates than they were of absolute fish size. Furthermore, RNA concentrations were better predictors of growth than RNA/DNA ratios. The strength of the regression between either RNA/DNA ratio or RNA and growth rate did not differ consistently among temperatures. Fish reared at warmer temperatures had lower concentrations of RNA for both a given growth rate and a given DNA concentration compared with cold-reared trout. Warm-reared fish also had lower concentrations of DNA and higher protein/DNA ratios than cold-reared trout when fish size was standardized. The concomitant decrease in both RNA and DNA concentrations resulted in marginally lower RNA/DNA ratios in warm-reared fish.

A respirometric analysis of fuel use during aerobic swimming at different temperatures in rainbow trout (Oncorhynchus mykiss)

1998 ◽  
Vol 201 (22) ◽  
pp. 3123-3133 ◽  
Author(s):  
JD Kieffer ◽  
D Alsop ◽  
CM Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Swimming Speed ◽  
Ammonia Excretion ◽  
Whole Body ◽  
Acclimation Temperature ◽  
Fish Swimming ◽  
Fuel Use ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Absolute Basis

Instantaneous fuel usage at 5 degreesC or 15 degreesC was assessed by measurement of rates of O2 consumption (O2), CO2 excretion (CO2) and nitrogenous waste excretion (nitrogen =ammonia-N + urea-N) in juvenile rainbow trout (Oncorhynchus mykiss) at rest and during swimming at 45 % and 75 % of aerobic capacity (Ucrit). After 2 weeks of training at approximately 1 body length s-1 (BL s-1), critical swimming speeds (approximately 3.0 BL s-1) and whole-body energy stores (total protein, lipids and carbohydrates) were identical in fish acclimated to 5 degreesC or 15 degreesC. O2 and CO2 increased with swimming speed at both temperatures and were higher at 15 degreesC than at 5 degreesC at all speeds, but the overall Q10 values (1.23-1.48) were low in these long-term (6 weeks) acclimated fish. The respiratory quotient (CO2/O2, approximately 0.85) was independent of both temperature and swimming speed. In contrast to O2 and CO2, the rate of ammonia excretion was independent of swimming speed, but more strongly influenced by temperature (Q10 1. 4-2.8). Urea excretion accounted for 15-20 % of nitrogen, was unaffected by swimming speed and showed a tendency (P<0.07) to be positively influenced by temperature at one speed only (45 % Ucrit). Nitrogen quotients (NQ nitrogen/O2) were generally higher in warm-acclimated fish, remaining independent of swimming speed at 15 degreesC (0.08), but decreased from about 0.08 at rest to 0.04 during swimming at 5 degreesC. Instantaneous aerobic fuel use calculations based on standard respirometric theory showed that both acclimation temperature and swimming speed markedly influenced the relative and absolute use of carbohydrates, lipids and proteins by trout. At rest, cold-acclimated trout used similar proportions of carbohydrates and lipids and only 27 % protein. During swimming, protein use decreased to 15 % at both speeds while the relative contributions of both lipid and carbohydrate increased (to more than 40 %). On an absolute basis, carbohydrate was the most important fuel for fish swimming at 5 degreesC. In contrast, resting fish acclimated to 15 degreesC utilized 55 % lipid, 30 % protein and only 15 % carbohydrate. However, as swimming speed increased, the relative contribution of carbohydrate increased to 25 %, while the protein contribution remained unchanged at approximately 30 %, and lipid use decreased slightly (to 45 %). On an absolute basis, lipid remained the most important fuel in fish swimming at 15 degreesC. These results support the concept that lipids are a major fuel of aerobic exercise in fish, but demonstrate that the contribution of protein oxidation is much smaller than commonly believed, while that of carbohydrate oxidation is much larger, especially at higher swimming speeds and colder temperature.

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