Cyclical growth in juvenile rainbow trout, Salmo gairdneri

1985 ◽  
Vol 63 (10) ◽  
pp. 2473-2474 ◽  
Author(s):  
G. F. Wagner ◽  
B. A. McKeown
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Weekly Basis ◽  
Growth Physiology ◽  
Juvenile Rainbow Trout ◽  
Cyclical Growth

The growth rate (weight) of 70 juvenile rainbow trout, monitored on a weekly basis for a period of 4 months, was observed to cycle, with alternating phases of accelerated and reduced growth every 3 to 4 weeks. The significance of this phenomenon is discussed in relation to recent studies on growth physiology in rats.

Effect of Growth Rate and Size of Fish on Rate of Intoxication by Waterfoorne Lead

1982 ◽  
Vol 39 (9) ◽  
pp. 1243-1251 ◽  
Author(s):  
Peter V. Hodson ◽  
D. George Dixon ◽  
Douglas J. Spry ◽  
D. M. Whittle ◽  
John B. Sprague
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Lake Trout ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Small Fish ◽  
Rainbow Smelt ◽  
Fish Size ◽  
Threshold Size ◽  
Juvenile Rainbow Trout

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

Assessment of the Acute Toxicity, Growth Impairment, and Flesh Tainting Potential of a Bleached Kraft Mill Effluent on Rainbow Trout (Salmo gairdneri)

1977 ◽  
Vol 34 (6) ◽  
pp. 869-878 ◽  
Author(s):  
D. M. Whittle ◽  
K. W. Flood
Keyword(s):  
Rainbow Trout ◽  
Acute Toxicity ◽  
Continuous Flow ◽  
Effluent Treatment ◽  
Salmo Gairdneri ◽  
Freshwater Ecosystem ◽  
Juvenile Rainbow Trout ◽  
Effluent Concentration ◽  
Kraft Mill Effluent ◽  
Kraft Mill

Static and continuous-flow bioassays utilizing juvenile rainbow trout (Salmo gairdneri) were conducted on a northern Ontario bleached kraft mill effluent to assess the range of acute toxicity and related sublethal effects. The acute toxicity of the total mill effluent, as determined by static bioassay procedures, ranged from a 96-h LC50 value of 14–49.0% vol/vol. The results of these bioassays depended on testing methodology and effluent treatment systems employed by the mill when samples were collected. Continuous-flow bioassays conducted on the effluent Produced 96-h LC50 values of 21.8 and 24.8% vol/vol. Growth rate of juvenile rainbow trout (1–2 g) held under continuous-flow conditions for 18 days was significantly reduced at 6% vol/vol effluent concentration (P < 0.05). Flavor of yearling rainbow trout [Formula: see text] exposed to 3% effluent for 48 h was significantly impaired (P < 0.05). This effluent concentration, the lowest level impairing flavor represents approximately 0.12 of the 96-h LC50 derived from continuous-flow bioassays. No significant flavor impairment was detected in fish exposed for 144 h to a 2% effluent concentration Flavor impairment at a 3% vol/vol effluent concentration, the most sensitive sublethal response measured in this study, may also be the most critical response when assessing the economic impact of a kraft mill discharge to a freshwater ecosystem.

Some Toxic Constituents of Chlorination-Stage Effluents from Bleached Kraft Pulp Mills

1981 ◽  
Vol 38 (7) ◽  
pp. 739-743 ◽  
Author(s):  
A. B. McKague
Keyword(s):  
Gas Chromatography ◽  
Rainbow Trout ◽  
Kraft Pulp ◽  
Pulp Mill ◽  
Salmo Gairdneri ◽  
Pulp Mills ◽  
Juvenile Rainbow Trout ◽  
Bleached Kraft Pulp ◽  
Toxic Materials ◽  
Kraft Pulp Mills

Constituents responsible for the toxicity of a sample of bleached kraft chlorination-stage effluent to juvenile rainbow trout (Salmo gairdneri) were investigated. Tetrachlorocatechol, 3,4,5-trichlorocatechol, and 2,6-dichlorohydroquinone were identified and evidence was obtained for the presence of other chlorodihydroxybenzenes in toxic acidic fractions of the sample. Concentrations of 0.46 mg/L 3,4,5-trichloro- and 0.74 mg/L tetrachloro-catechol were estimated in the sample by analytical gas chromatography. Toxic materials in the nonacidic fraction were not identified although the nontoxic dichloromethyl methyl sulfone was isolated.Key words: chlorination-stage effluent, toxicity, pulp mill, chlorocatechols, chlorodihydroxybenzenes

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
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
New Zealand ◽  
Swimming Performance ◽  
Salmo Gairdneri ◽  
Swimming Ability ◽  
Fish Swimming ◽  
Fish Size ◽  
Swimming Time ◽  
Performance Profiles

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.

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.

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