Accumulation of Cadmium by Rainbow Trout, Salmo gairdneri, during Extended Exposure

1988 ◽  
Vol 45 (6) ◽  
pp. 1045-1053 ◽  
Author(s):  
Michael A. Giles

Adult rainbow trout, Salmo gairdneri, were exposed to 3.6 and 6.4 μg Cd/L for 178 d. Cadmium accumulated most rapidly in gill tissue which became saturated at levels 100-fold higher than controls within 24 and 52 d in the high- and low-metal exposures, respectively. Liver cadmium increased 250- to 400-fold over the test period but accumulation exhibited a plateau between 52 and 129 d followed by a rapid rise by 178 d. Kidney cadmium increased consistently throughout the test period to levels approximately 50- to 100-fold higher than control values. Cadmium in the gut and skin increased 10- and 5-fold, respectively, while no increase was recorded in white muscle. A maximum of 2.1% of the cadmium available in a commercial diet (0.2 μg Cd/g dry food} was accumulated in control fish. Although cadmium was not detected in the urine, urinary zinc excretion was elevated in trout exposed to 6.4 μg Cd/L such that 7 mol of zinc was excreted per 1 mol of cadmium accumulated during the initial 24 d of exposure. The whole-body burden of cadmium increased linearly with time in both treatments with a time constant of 0.366 and 0.554%/d for trout exposed to 3.6 and 6.4 μg Cd/L, respectively.

1987 ◽  
Vol 44 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Darrel Jon Laurén ◽  
D. G. McDonald

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.


1984 ◽  
Vol 41 (11) ◽  
pp. 1592-1600 ◽  
Author(s):  
Karl D. Shearer

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.


1988 ◽  
Vol 45 (1) ◽  
pp. 32-41 ◽  
Author(s):  
D. J. Spry ◽  
P. V. Hodson ◽  
C. M. Wood

Rainbow trout, Salmo gairdneri, were fed purified diets with zinc concentrations ranging from deficient to excessive (1, 90, 590 μg Zn∙g−1) and simultaneously exposed to a range of waterborne [Zn] (7, 39, 148, 529 μg Zn∙L−1). After 1 wk, fish fed the deficient diet, at ambient waterborne [Zn], had low plasma [Zn] which decreased further during the 16-wk experiment. Growth ceased after 12 wk; hematocrit and plasma protein were depressed. Both whole body [Zn] and body burden decreased by 16 wk, but most other elements were elevated. Increasing waterborne [Zn] alone increased plasma [Zn], whole body [Zn], and growth in a graded manner and normalized hematocrit, plasma protein, and other whole body elements. Increasing dietary [Zn] to 90 μg Zn∙g−1 at ambient waterborne [Zn] prevented depression of plasma [Zn] and permitted normal growth and whole body [Zn]. Zinc uptake from water, probably across the gills, was independent of uptake from the diet since at any dietary [Zn], increasing the waterborne [Zn] resulted in increased whole body [Zn]. Even when dietary [Zn] was adequate, the waterborne contribution was as high as 57%, and 100% when the dietary [Zn] was deficient. There were no toxic effects on any of the variables measured.


1976 ◽  
Vol 33 (6) ◽  
pp. 1335-1342 ◽  
Author(s):  
Patrick F. Lett ◽  
G. J. Farmer ◽  
F. W. H. Beamish

The influence of sublethal concentrations of total copper on the appetite, growth, and proximate body composition of rainbow trout (Salmo gairdneri) held in hard water (365 mg/liter) was measured over a 40-day interval. The initial response of trout exposed to concentrations of copper ranging from 0.0 to 0.3 mg/liter (the 96-h LC50 was 0.25–0.68) was the cessation of feeding. Thereafter, food intake gradually returned to amounts observed for control fish, the rate of return of appetite being dependent on copper concentration and ration level. Growth rate of trout exposed to copper (0.075–0.225 mg/liter) and fed rations of either 0.25 or 1.5% dry food wt/wet fish wt per day was initially depressed but approached values observed for control fish near the end of the 40-day interval. During this period, lipid, protein, and moisture offish exposed to copper did not change significantly. Initial growth retardation was not attributable to the inability of copper-exposed fish to digest their daily rations. Results are discussed in terms of the ability offish to adapt to stress imposed by sublethal concentrations of heavy metals.


1989 ◽  
Vol 147 (1) ◽  
pp. 147-168 ◽  
Author(s):  
STEVE F. PERRY ◽  
PIERRE LAURENT

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.


1988 ◽  
Vol 45 (11) ◽  
pp. 2003-2009 ◽  
Author(s):  
T. Pouliot ◽  
J. de la Noüe

We assessed the influence of hypoxia, which is likely to reduce the productivity of fish culture, on the digestibility of nutrients in rainbow trout (Salmo gairdneri). Rainbow trout (seven to each diet) were kept for 8 d in water with an oxygen saturation level of 40.0 ± 4.0%, while control fish were kept in 89.4 ± 4.2% oxygen-saturated water. Three isonitrogenous and isocaloric diets composed of different sources of protein (animal, plant, and mixed) were used. The apparent digestibility coefficients (ADC) were calculated by the indirect method (chromic oxide) after the automatic collection of feces. The experimental hypoxia used did not change the ADC for protein (total nitrogen), gross energy, or dry matter. The amino acids only showed a tendency for better absorption: proline, glycine, alanine, and tryptophan had a significantly higher ADC (P < 0.05) in experimental fish than in control fish when the animal protein based diet was used. Finally, we noted that feed intake was diet dependent. In contrast with what we observed with the commercial (mixed protein sources) and plant protein based diets, the fish receiving the animal protein based diet maintained a normal (or returning to normal) feed intake when they were subjected to hypoxia.


1986 ◽  
Vol 126 (1) ◽  
pp. 499-512 ◽  
Author(s):  
PATRICIA WRIGHT ◽  
TOM HEMING ◽  
DAVID RANDALL

We investigated the pH of interlamellar water of trout (Salmo gairdneri) by following changes in the downstream pH of expired water using a stopped-flow method. As water flowed over the gills of control fish, there was a significant decrease in water pH. Acetazolamide added to the water increased the CO2 disequilibrium, while carbonic anhydrase (CA) eliminated the CO2 disequilibrium relative to control water. Mucus excreted by the fish was found to contain CA activity by the pH-stat technique. We conclude water acidification is due to the conversion of excreted CO2 to HCO3− and H+ at the gill surface.


1991 ◽  
Vol 69 (3) ◽  
pp. 578-582 ◽  
Author(s):  
A. Kurt Gamperl ◽  
Dan L. Schnurr ◽  
E. Don Stevens

Fast-start acceleration performance of rainbow trout (Salmo gairdneri) was measured after 9 weeks of sprint training (30°s duration, every 2nd day). Response latency and time required to complete the first two stages of a fast start were unaffected by the sprint-training protocol. Maximum acceleration (trained 1985 ± 176 (SE) cm/s2; control 1826 ± 144 cm/s2) and maximum velocity (trained 130 ± 7 cm/s; control 134 ± 14 cm/s) were also not significantly different following training. However, trained fish reached high rates of acceleration before control (untrained) fish. Thus, acceleration was higher in trained fish from 20 to 35 ms postshock. When fish are separated by start type, trained fish consistently had greater acceleration than control fish between 30 and 45 ms postshock. Alterations in fast-start performance due to sprint training may improve predator avoidance ability. Sprint training did not change critical swimming speed as measured using two separate protocols.


2006 ◽  
Vol 63 (2) ◽  
pp. 412-422 ◽  
Author(s):  
Victoria A Kjoss ◽  
Chris M Wood ◽  
D Gordon McDonald

The effects of different ligands on the bioavailability of dietary copper (Cu) and zinc (Zn) to fish have not been thoroughly investigated. We therefore exposed juvenile rainbow trout (Oncorhynchus mykiss; ~200 mg body weight) to control food or to food supplemented with different Cu (~400 µg·g–1 food) or Zn (~1000 µg·g–1 food) compounds. Tissue metal accumulation was compared among groups. Fish fed CuO showed no differences in tissue Cu concentrations relative to control fish, suggesting that Cu was not readily available for uptake in this form. In contrast, Cu in the form of CuSO4, Cu-proteinate, or Cu-lysine was much more available for uptake, resulting in substantial increases in liver, gut tissue, and whole-body Cu concentrations during the loading phase and decreases during depuration, although liver and whole-body levels remained elevated after 2 weeks. We found no differences in tissue Cu accumulation among these three complexes. There were no effects on growth. For Zn, we found no differences among any of the treatments, including controls, in Zn accumulation or growth. Overall, there was homeostasis of whole-body and tissue-specific Zn concentrations despite the large differences in dietary Zn loads.


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

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.


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