Differences in Swimming Performance Among Strains of Rainbow Trout (Salmo gairdneri)

1977 ◽  
Vol 34 (2) ◽  
pp. 304-307 ◽  
Author(s):  
Allan E. Thomas ◽  
Michael J. Donahoo

Swimming performance profiles, relating fish size to swimming time, were established for three strains of rainbow trout (Salmo gairdneri). No differences were found in slope of regressions; only in level at each size of fish. Swimming performances of New Zealand and Sand Creek strains did not differ, but were superior to the Manchester strain. In stamina results from 189-day-old fish from individual matings of seven strains and various crosses, similar strains and crosses had closely matching profiles whereas profiles of unrelated groups were variable. Comparison of slowest, average, and fastest growing fish within the New Zealand strain showed that swimming ability was not related to growth rate.

1982 ◽  
Vol 39 (9) ◽  
pp. 1243-1251 ◽  
Author(s):  
Peter V. Hodson ◽  
D. George Dixon ◽  
Douglas J. Spry ◽  
D. M. Whittle ◽  
John B. Sprague

Three experiments were undertaken to test the null hypotheses that increasing fish size and growth rate do not increase the rate of intoxication of fish by lead. The first experiment demonstrated that there were no significant correlations between weight of fish and either whole-body or blood lead concentrations in feral lake trout (Salvelinus namaycush). The whole-body lead concentration of rainbow smelt (Osmerus mordax) was, however, negatively correlated to wet weight.During the second experiment, an 8-d laboratory exposure of rainbow trout (Salmo gairdneri) to 100 μg/L of total waterborne lead caused a greater uptake of lead by opercular bone in small fish than in larger fish. No relationship was apparent between fish weight and uptake of lead by blood.Chronic exposure of juvenile rainbow trout to lead results in the development of black tails, a symptom of neurotoxicity. The final experiment related the incidence and prevalence of black tails to size and growth rate (ration level) of juvenile rainbow trout chronically exposed to 543 μg/L of total waterborne lead starting with the sac-fry stage. At weights below a common threshold size of 1.5–2.5 g, no black tails occurred; above this threshold the incidence of black tails was a function of growth rate, i.e. the rate at which fish reached the threshold size. The prevalence of black tails was always less in slowly growing fish.These experiments demonstrated that the rate of intoxication by lead, as indicated by uptake rates into tissues and the incidence and prevalence of a symptom of neurotoxicity, did not increase with fish size, but rather with growth rate.Key words: fish, toxicity, lead, fish size, growth rate, neurotoxicity, uptake


1981 ◽  
Vol 32 (6) ◽  
pp. 967 ◽  
Author(s):  
RWJ Pidgeon

The diets and growth rates of rainbow trout in the Wollomombi and Guy Fawkes Rivers in northern New South Wales were examined. The growth rate of trout in the Wollomombi River was much higher than that of fish in the Guy Fawkes River. Spearman rank correlation coefficients indicated that stream type was more important than fish size in determining the composition of the diet of the trout. Benthic invertebrates formed the largest component of the diet in both streams: 66.0 and 63.0% of ash-free dry weight (AFDW) in the Wollomombi River and the Guy Fawkes River, respectively. Trout in the Wollomombi River consumed more nektonic prey (33.3% of AFDW) than fish in the Guy Fawkes River (3.7% of AFDW). In contrast, surface food (aquatic imagines and terrestrial insects) made up a much higher proportion of the diet of trout in the Guy Fawkes River (33.9% of AFDW) than in the Wollomombi River (0.6% of AFDW). Crayfish were a major component of the diet (in terms of AFDW) in both streams, their proportions increasing with fish size. The significance of crayfish in relation to fish growth is discussed.


1985 ◽  
Vol 42 (3) ◽  
pp. 488-493 ◽  
Author(s):  
Ernest J. Mellas ◽  
James M. Haynes

Implicit in biotelemetry studies is the assumption that transmitter attachment does not affect fish behavior or performance. We conducted experiments to determine effects of external, surgical, and stomach tag attachments on the swimming performance and behavior of rainbow trout (Salmo gairdneri) and white perch (Morone americana). Only one rainbow trout changed dominance rank after dummy tag attachment. Subordinate fish had significantly lower weights than subdominant and dominant fish, but there were no significant differences in exhaustion times. Externally tagged trout had significantly lower exhaustion times than other tagged groups and controls. There was no significant difference in exhaustion times among tagged white perch and controls. Externally and surgically tagged perch contracted serious fungal infections during a 45-d survival study; however, few disease and no survival problems among tagged and untagged rainbow trout were noted up to 21 d. With all factors taken into account, it appears that stomach tagging is the best method of transmitter attachment, except when regurgitation and/or stomach atrophy are likely to be encountered.


1998 ◽  
Vol 55 (7) ◽  
pp. 1583-1590 ◽  
Author(s):  
T Ryan Gregory ◽  
Chris M Wood

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.


1990 ◽  
Vol 68 (7) ◽  
pp. 1494-1498 ◽  
Author(s):  
Moira M. Ferguson ◽  
Roy G. Danzmann

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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
P. Vezza ◽  
F. Libardoni ◽  
C. Manes ◽  
T. Tsuzaki ◽  
W. Bertoldi ◽  
...  

Abstract Systematic experiments on European eel (Anguilla anguilla) in their juvenile, early life stage (glass eel), were conducted to provide new insights on the fish swimming performance and propose a framework of analysis to design swimming-performance experiments for bottom-dwelling fish. In particular, we coupled experimental and computational fluid dynamics techniques to: (i) accommodate glass eel burst-and-coast swimming mode and estimate the active swimming time (tac), not considering coast and drift periods, (ii) estimate near-bottom velocities (Ub) experienced by the fish, rather than using bulk averages (U), (iii) investigate water temperature (T) influence on swimming ability, and (iv) identify a functional relation between Ub, tac and T. Results showed that burst-and-coast swimming mode was increasingly adopted by glass eel, especially when U was higher than 0.3 ms-1. Using U rather than Ub led to an overestimation of the fish swimming performance from 18 to 32%, on average. Under the range of temperatures analyzed (from 8 to 18 °C), tac was strongly influenced and positively related to T. As a final result, we propose a general formula to link near-bottom velocity, water temperature and active swimming time which can be useful in ecological engineering applications and reads as $${\rm{U}}_{\rm{b}}=0.174\cdot \left({{\rm{t}}_{\rm{ac}}}^{-0.36}\cdot {\rm{T}}^{0.77}\right)$$ U b = 0.174 · t ac - 0.36 · T 0.77 .


1972 ◽  
Vol 29 (7) ◽  
pp. 1005-1009 ◽  
Author(s):  
Donald L. Horak

No conclusive evidence was found in tests from 1966 to 1969 in either lentic or lotic environments to support the hypothesis that hatchery-reared rainbow trout (Salmo gairdneri) with a high-stamina index had a higher survival potential than those whose stamina index was low. Physical stamina was measured by determining the length of time each fish could withstand sustained swimming in a specially constructed stamina tunnel. For high-stamina rating, fish swam in the tunnel for 80 min; for low stamina, 1–10 min.In tests of reproducibility of stamina ratings, improved swimming ability of low-stamina fish was demonstrated upon retesting in the tunnel. In 1970, with retested fish, still no evidence was found to indicate higher survival of fish rated as high in stamina. Additional studies are needed to determine if performance of hatchery-reared salmonids in a stamina tunnel is a valid indicator of their survival potential in the wild.


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