Influence of pH on the Acute Lethality of Fenitrothion, 2,4-D, and Aminocarb and Some pH-Altered Sublethal Effects of Aminocarb on Rainbow Trout (Salmo gairdneri)

1988 ◽  
Vol 45 (2) ◽  
pp. 287-293 ◽  
Author(s):  
K. G. Doe ◽  
W. R. Ernst ◽  
W. R. Parker ◽  
G. R. J. Julien ◽  
P. A. Hennigar
Keyword(s):  
Rainbow Trout ◽  
Sublethal Effects ◽  
Acetylcholinesterase Activity ◽  
Whole Body ◽  
Toxicity Tests ◽  
Salmo Gairdneri ◽  
Control Range ◽  
Decreasing Ph ◽  
Influence Of Ph ◽  
Brain Acetylcholinesterase

Three pesticides, fenitrothion, 2,4-D, and aminocarb, were tested in static 96-h acute lethal toxicity tests using fingerling rainbow trout (Salmo gairdneri) at pH 4.6, 5.6, 6.9, and 8.5. The toxicity of aminocarb, a base, increased significantly with increasing pH. Conversely, the toxicity of the acidic pesticide 2,4-D increased with decreasing pH. The toxicity of the neutral pesticide fenitrothion did not change significantly with changing pH. Subsequent tests were performed on trout fingerlings with aminocarb to determine the effect of two exposure pH's on brain acetylcholinesterase activity and whole-body aminocarb residue. Brain acetylcholinesterase was found to be inversely proportional to whole-body aminocarb content of fish. In fish exposed at pH 4.6, brain acetylcholinesterase was maximally depressed at 6 h, after which it recovered to within the control range. Whole-body aminocarb concentrations rose to a maximum within 6 h and subsequently declined to low levels. In fish exposed at pH 8.2, brain acetylcholinesterase dropped below the control range by 1 h and remained low until all fish died by 72 h. A maximum whole-body aminocarb concentration was reached within 1 h and remained elevated until the fish died. Several explanations for the observed results are presented.

Role of Exposure Duration in Hydrogen Ion Toxicity to Brook (Salvelinus fontinalis) and Rainbow Trout (Salmo gairdneri)

1989 ◽  
Vol 46 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Lawrence R. Curtis ◽  
Wayne K. Seim ◽  
Lisbeth K. Siddens ◽  
Debra A. Meager ◽  
Richard A. Carchman ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Exposure Duration ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Recovery Period ◽  
Whole Body ◽  
Toxicity Tests ◽  
Salmo Gairdneri ◽  
Electrolyte Balance ◽  
Toxicant Concentration

Acidification of streams and rivers associated with rainstorm or snowmelt events is often episodic as are many environmental introductions of toxic substances. We examined the toxicity of continuous or intermittent exposures to sulfuric acid (H+) to brook trout (Salvelinus fontinalis) embryos, alevins, and fry. Acute toxicity tests were conducted with juvenile rainbow trout (Salmo gairdneri). These studies permitted evaluation of key components of intermittent exposures (toxicant concentration, exposure duration, and recovery period) on mortality, reduced growth, and perturbed electrolyte balance. Lethality of H+ markedly changed with developmental stage of brook trout. Resistance of the chorion to H+ penetration probably protected embryonic fish, while hatching and onset of active swimming exacerbated H+ toxicity. Response surface methods demonstrated that between pH 4 and 7, time–concentration relationships for H+ toxicity were greatly influenced by exposure duration and peak concentration but little by length of recovery period. Daily pulses at pH 4 with duration as short 4.5 h produced marked mortality after 90 d. This did not occur after 4–60 d of testing. Whole-body Na+, K+, and Ca2+ concentrations of brook trout were negatively correlated with mean H+ concentrations after 90 d of exposure. Cation depletion appeared to be a more sensitive index of chronic, sublethal H+ toxicity than reduced growth.

scholarly journals Adaptational Responses of Rainbow Trout to Lowered External Nacl Concentration: Contribution of the Branchial Chloride Cell

1989 ◽  
Vol 147 (1) ◽  
pp. 147-168 ◽  
Author(s):  
STEVE F. PERRY ◽  
PIERRE LAURENT
Keyword(s):  
Rainbow Trout ◽  
Surface Area ◽  
Fresh Water ◽  
Primary Response ◽  
Chloride Cell ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Apical Surface ◽  
Ionic Fluxes ◽  
Area 5

1. Whole-body ionic fluxes and gill chloride cell (CC) morphology were monitored in rainbow trout (Salmo gairdneri) exposed acutely or chronically to natural fresh water (NFW; [Na+]=0.120 mmoll−1; [Cr]=0.164 mmoll−1) or artificially prepared fresh water with reduced [NaCl] (AFW; [Na+]=0.017 mmoll−1; [CT]=0.014 mmoll−1). 2. Net fluxes of Na+ (JnetNa) and Cl− (JnetCl) became extremely negative (indicating net NaCl loss to the environment) upon immediate exposure to AFW exclusively as a result of reduced NaCl influx (JinNa and JinNa). JnetNa and JnetCl were gradually restored to control rates during prolonged (30 days) exposure to AFW. 3. The restoration of JnetCl in AFW was due both to increased JinCl and to reduced Cl− efflux (JoutCl) whereas the primary response contributing to the restoration of JnetNa a t was an increase of JNain. 4. The total apical surface area of branchial CCs exposed to the external environment increased markedly after 24 h in AFW and remained elevated for 1 month as a consequence of enlargement of individual CCs and, to a lesser extent, increased CC density. JinNa and JinNa were correlated significantly with total CC apical surface area. 5. Plasma cortisol levels rose transiently in fish exposed to AFW. Treatment of NFW-adapted fish with cortisol for 10 days (a protocol known to cause CC proliferation) caused pronounced increases in JinCl and JinNa, as measured in both NFW and AFW. 6. These results suggest that an important adaptational response of rainbow trout to low environmental [NaCl] is cortisol-mediated enlargement of branchial epithelial CCs which, in turn, enhances the NaCl-transporting capacity of the gill as a result of the proliferation of Na+ and Cl− transport sites.

Acclimation to Copper by Rainbow Trout,Salmo gairdneri: Biochemistry

1987 ◽  
Vol 44 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Darrel Jon Laurén ◽  
D. G. McDonald
Keyword(s):  
Rainbow Trout ◽  
Specific Activity ◽  
Gill Tissue ◽  
Microsomal Protein ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Copper Accumulation ◽  
Copper Exposure ◽  
Copper Uptake ◽  
Liver Copper

Whole body, gill, and liver copper uptake, gill Na+-K+-ATPase specific activity, and gill and liver acid-soluble thiols (AST), glutathione, and cysteine of rainbow trout (Salmo gairdneri) were measured during 28 d of exposure to 55 μg copper∙L−1. Na+-K+-ATPase specific activity was inhibited by 33% within 24 h of copper exposure, but this was compensated by a significant increase in microsomal protein so that the total Na+-K+-ATPase activity per milligram of gill tissue returned to normal by day 14. There was no accumulation of copper and no increase in AST, glutathione, or cysteine in the gill. However, after 7 d of exposure, hepatic AST and glutathione had increased by about 2 times, and a sulfhydryl-rich, acid-soluble protein, tentatively identified as metallothionein, increased by 2.8 times. Copper accumulation was highest in the liver, but other tissues also accumulated copper.

Sublethal Effects of Environmental Acidification on Rainbow Trout (Salmo gairdneri)

1979 ◽  
Vol 36 (1) ◽  
pp. 84-87 ◽  
Author(s):  
C. M. Neville
Keyword(s):  
Rainbow Trout ◽  
Species Differences ◽  
Sublethal Effects ◽  
Anaerobic Respiration ◽  
Acid Group ◽  
Salmo Gairdneri ◽  
Significant Difference ◽  
Caudal Vein ◽  
Erythrocyte Concentration ◽  
Oxygen Carrying Capacity

Dorsal aorta blood samples were taken from cannulated rainbow trout (Salmo gairdneri) exposed to pH 4.0 (acid group) or pH 7.0 (controls) in normocapnic conditions at 10 °C. Over a 5-d period there was a significant gradual decrease in pH and total CO2 in the acid group but no significant difference in pO2 and lactate compared to the controls. After uncannulated rainbow trout were exposed to the same conditions for 12 d there were significant increases in hemoglobin, hematocrit, and erythrocyte levels in caudal vein samples from the acid group. The results show that rainbow trout exposed to acid without hypercapnia develop acidaemia which is not a result of anaerobic respiration. The increase in erythrocyte concentration probably offsets the effects of acidaemia upon blood oxygen carrying capacity. Differences in ambient pCO2 and/or species differences could account for varying acid-base values in acid exposed fish reported by different workers. Key words: environmental acidification, acidaemia, lactate, pH, total carbonate, fish

Effect of Sulfite Dechlorination on the Accumulation of Waterborne Lead by Rainbow Trout (Salmo gairdneri)

1985 ◽  
Vol 42 (4) ◽  
pp. 841-844 ◽  
Author(s):  
Peter V. Hodson ◽  
Douglas J. Spry
Keyword(s):  
Rainbow Trout ◽  
Sodium Sulfite ◽  
Limit Of Detection ◽  
Aquatic Toxicity ◽  
Blood Lead ◽  
Toxicity Tests ◽  
Salmo Gairdneri ◽  
Residual Chlorine ◽  
Lead Levels ◽  
Laboratory Water

Chlorine can be removed from laboratory water supplies by reduction with sodium sulfite, but sulfite complexation of metals may bias aquatic toxicity tests. We tested the effect of waterborne sulfite on the accumulation of waterborne lead by rainbow trout (Salmo gairdneri). After 96 h, the blood lead levels of trout exposed to both 100 μg lead/L and 440 μg sodium sulfite/L were lower than those exposed to lead alone. The highest level of sodium sulfite having no effect on blood lead was 20 μg/L. The addition of 200–300 μg sodium sulfite/L to our water supply after charcoal filtration removed residual chlorine levels rapidly and completely. This reaction, and other possible reactions with organic matter, always reduced measureabie sulfite levels to less than 1 μg/L (limit of detection), a level much lower than those tested. Hence, sulfite dechlorination should not interfere with metal bioassays.

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

The Influence of pH, Water Hardness, and Alkalinity on the Acute Lethality of Zinc to Rainbow Trout (Salmo gairdneri)

1985 ◽  
Vol 42 (4) ◽  
pp. 731-736 ◽  
Author(s):  
R. W. Bradley ◽  
J. B. Sprague
Keyword(s):  
Rainbow Trout ◽  
Water Hardness ◽  
Salmo Gairdneri ◽  
Total Hardness ◽  
Zinc Toxicity ◽  
Carbonate Alkalinity ◽  
Effects Of Ph ◽  
Order Of Magnitude ◽  
Low Toxicity ◽  
Influence Of Ph

The acute lethality of dissolved zinc to rainbow trout (Salmo gairdneri) was significantly increased at higher pH and lower hardness levels. Changes in pH from 5.5 to 7.0 increased zinc toxicity by factors of 2 to 5, depending on total hardness levels. A decrease in hardness from 386 to 31 mg CaCO3/L increased zinc toxicity by more than an order of magnitude at both pH levels. These effects of pH and hardness were not caused by changes in the chemical speciation of zinc. An increase in carbonate alkalinity from 8.4 to 24 mg CaCO3/L at pH 7.0 did not significantly alter zinc toxicity at either hardness level. Thus, carbonate alkalinity is not an important factor at or below pH 7.0. At low hardness, dissolved zinc was more than 10 times as toxic at pH 9.0 as at pH 5.5. Two competing mechanisms appear to operate: as the pH rises, dissolved zinc becomes increasingly toxic, but at higher pH levels it is increasingly replaced by zinc precipitate, which is of very low toxicity to fish.

Changes in Elemental Composition of Hatchery-Reared Rainbow Trout, Salmo gairdneri, Associated with Growth and Reproduction

1984 ◽  
Vol 41 (11) ◽  
pp. 1592-1600 ◽  
Author(s):  
Karl D. Shearer
Keyword(s):  
Life Cycle ◽  
Rainbow Trout ◽  
Elemental Composition ◽  
Body Burden ◽  
Dry Weight ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Gonad Maturation ◽  
Fish Size ◽  
Weight Concentration

By examining a group of rainbow trout (Salmo gairdneri) over their life cycle (ova to 1500 g), 1 found that their elemental composition was determined by fish size, stage of life cycle (prefeeding, juvenile, post-juvenile), and reproductive state. Fish were fed practical diets and were reared under hatchery conditions. Whole body elemental concentrations of Ca, Cu, Fe, K, Mg, Mn, Na, P, Sr, and Zn were size dependent prior to sexual maturity. Rates of elemental accumulation in relation to weight gain were higher in juveniles than in adult fish. Reduced somatic concentrations of Mn, Fe, and Zn were observed during gonad maturation in female but not in male trout. Tissue concentrations of some elements remained constant over the duration of the study, while others increased or decreased linearly with increasing fish size. Tables and equations 1 present will enable the normal tissue and whole body elemental composition of rainbow trout at any size to be determined. My results indicate that body burden or wet weight concentration are better indicators of elemental status than dry weight concentration and that comparison of elemental levels between treatment groups in dietary experiments should be made on the basis of a standard-sized fish or by comparing the rates of elemental deposition with growth.

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