Deposition of aluminum in the gill epithelium of rainbow trout (Salmo gairdneri Richardson) subjected to sublethal concentrations of the metal

1987 ◽  
Vol 65 (3) ◽  
pp. 647-656 ◽  
Author(s):  
John H. Youson ◽  
Christine M. Neville
Keyword(s):  
Rainbow Trout ◽  
Epithelial Cells ◽  
Organic Acid ◽  
Control Fish ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Gill Epithelium ◽  
Epithelial Surface ◽  
X Ray ◽  
Sublethal Concentrations

Rainbow trout (Salmo gairdneri Richardson) were exposed to acid and sublethal concentrations of inorganic aluminum (1.6 μM at pH 6.1; 2.8 μM at pH 5.5, 5.0, and 4.5); aluminum was also administered in combination with organic acid at pH 4.5 and 5.0. The gill epithelium was examined by transmission electron microscopy and by electron probe X-ray microanalysis. Control fish at pH 7.3 without aluminum showed normal morphology but increased acidity and (or) decreased hardness resulted in a greater exposure of chloride cells at the epithelial surface. All fish exposed to aluminum had electron-dense particles on the surface of the respiratory (pavement) epithelial cells and chloride cells of the gills and most cells had these deposits in varying concentrations within cytoplasmic vacuoles and dense bodies. It was shown by X-ray microanalysis that the deposits contained aluminum. Increased acidity did not alter the pattern of distribution of aluminum particles but a heavy concentration of this metal followed the addition of organic acid. The accumulation of aluminum on and within epithelial cells and increased exposure of chloride cells in the gills could reflect decreased oxygen uptake and increased ion loss in trout, and probably are responsible for the toxicity of aluminum to fish in an acid environment.

Ultrastructural and Clinicopathological Studies on the Toxicity of Cationic Acrylamide-based Flocculant to Rainbow Trout

1987 ◽  
Vol 24 (1) ◽  
pp. 34-43 ◽  
Author(s):  
M. Albassam ◽  
J. Moore ◽  
A. Sharma
Keyword(s):  
Rainbow Trout ◽  
Epithelial Cells ◽  
Blood Vessels ◽  
Cell Injury ◽  
Basement Membranes ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Apical Plasma Membrane ◽  
Plasma Sodium ◽  
Secondary Lamellae

Rainbow trout (Salmo gairdneri) of two age groups were exposed to a cationic acrylamide-based flocculant at various concentrations in static bioassay chambers. At lethal concentrations the flocculant produced severe gill alterations in all fish. The principal alterations were necrosis and separation of the respiratory epithelial cells covering secondary lamellae. Many necrotic chloride cells were also seen, their apical plasma membrane was destroyed, and mitochondria were swollen with separated cristae. An influx of a large amount of fluid into the interstitial spaces caused partial or complete separation of subepithelial spaces from the covering epithelial cells and basement membranes of underlying blood vessels. Clinicopathological alterations included marked decreases in blood pH, partial pressure of oxygen, bicarbonate and plasma sodium, and chloride concentrations. Hematocrit, total protein, and blood glucose were increased. Fish exposed to sublethal concentrations had gill alterations characterized by hypercellularity and thickening of the secondary lamellae. These were due to undifferentiated cell proliferation and macrophage and lymphocyte infiltration between the covering epithelial cells and the underlying blood vessels. Macrophages and undifferentiated cells had large phagolysosomes containing cytoplasmic organelles, an indication of cell injury and increased turnover.

Effect of Copper on Some Aspects of the Bioenergetics of Rainbow Trout (Salmo gairdneri)

1976 ◽  
Vol 33 (6) ◽  
pp. 1335-1342 ◽  
Author(s):  
Patrick F. Lett ◽  
G. J. Farmer ◽  
F. W. H. Beamish
Keyword(s):  
Rainbow Trout ◽  
Hard Water ◽  
Initial Response ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Initial Growth ◽  
Ration Level ◽  
Dry Food ◽  
Effect Of Copper ◽  
Sublethal Concentrations

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.

Apparent Digestibility in Rainbow Trout (Salmo Gairdneri): Influence of Hypoxia

1988 ◽  
Vol 45 (11) ◽  
pp. 2003-2009 ◽  
Author(s):  
T. Pouliot ◽  
J. de la Noüe
Keyword(s):  
Rainbow Trout ◽  
Feed Intake ◽  
Animal Protein ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Apparent Digestibility ◽  
Oxygen Saturation Level ◽  
Gross Energy ◽  
Isocaloric Diets ◽  
Different Sources

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.

Zinc Influx Across the Isolated, Perfused Head Preparation of the Rainbow Trout (Salmo gairdneri) in Hard and Soft Water

1988 ◽  
Vol 45 (12) ◽  
pp. 2206-2215 ◽  
Author(s):  
Douglas J. Spry ◽  
Chris M. Wood
Keyword(s):  
Steady State ◽  
Rainbow Trout ◽  
Hard Water ◽  
Soft Water ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
First Order ◽  
Scanning Electron Micrography ◽  
Primary Substrate ◽  
Stimulation Of

At a waterborne [Zn] of 1.9 mg∙L−1 in hard water (~1 mmol Ca∙L−1), Zn influx across an isolated, saline-perfused head preparation of rainbow trout (Salmo gairdneri) was about 1.5 nmol∙kg−1∙h−1 through the lamellar pathway and about 1 nmol∙kg−1∙h−1 through the filamental route. Flux rates came rapidly to steady state in both pathways. Trout preexposed to artificial soft water (~0.05 mmol Ca∙L−1) for 5 d showed differential stimulation of flux rates to about 42 and 5 nmol Zn∙kg−1∙h−1 through the lamellar and filamental pathways, respectively. Under these conditions, steady-state fluxes across the lamellae did not occur until 15–20 min after the start of perfusion. Preparations from hardwater-acclimated trout tested in soft water gave typical hardwater fluxes showing that these changes in influx were not simply due to acute exposure of the gill surface to low waterborne [Ca]. Influxes in softwater trout, studied over [Zn] from 0.4 to 7.5 mg Zn∙L−1, revealed a saturable, first-order uptake with apparent Jmax and Km of 150 nequiv∙kg−1∙h−1 and 1.5 mg Zn∙L−1 (23 μmol∙L−1), respectively. Because the apparent Km is in the toxic range, Zn is clearly not the primary substrate. Scanning electron micrography revealed hypertrophy and increased apical exposure of chloride cells; this stimulation, coupled with the increase in Zn influx, suggests that chloride cells may be the site of entry of Zn across the gill.

scholarly journals The pattern of carbon dioxide excretion in the rainbow trout Salmo gairdneri

1978 ◽  
Vol 72 (1) ◽  
pp. 17-24
Author(s):  
M. S. Haswell ◽  
D. J. Randall
Keyword(s):  
Carbon Dioxide ◽  
Rainbow Trout ◽  
Carbonic Anhydrase ◽  
Severe Anaemia ◽  
Salmo Gairdneri ◽  
Gill Epithelium ◽  
Acid Base ◽  
Plasma Bicarbonate ◽  
O2 Delivery ◽  
Co2 Excretion

1. Patterns of carbon dioxide excretion were investigated in rainbow trout (Salmo gairdneri). 2. The loss of erythrocytic carbonic anhydrase caused by severe anaemia does not affect acid/base regulation or the ability of fish to excrete CO2. 3. Bicarbonate excretion across the saline-perfused gills of trout is significant even though residence time for the saline in the gills is only 1--3 s. CO2 excretion across these saline-perfused gills is blocked by the carbonic anhydrase inhibitor, diamox. 4. The excretion of CO2 in fish is via the movement of plasma bicarbonate into the gill epithelium where branchial carbonic anhydrase catalyses the production of CO2. Fish can adjust pH by regulating bicarbonate movement across the gills. 5. The erythrocytic carbonic anhydrase is not necessary for CO2 excretion in the gills but is involved in facilitating Bohr and Root shifts to augment O2 delivery in the tissues.

scholarly journals Downstream pH Changes in Water Flowing Over the Gills of Rainbow Trout

1986 ◽  
Vol 126 (1) ◽  
pp. 499-512 ◽  
Author(s):  
PATRICIA WRIGHT ◽  
TOM HEMING ◽  
DAVID RANDALL
Keyword(s):  
Rainbow Trout ◽  
Carbonic Anhydrase ◽  
Control Fish ◽  
Salmo Gairdneri ◽  
Stopped Flow ◽  
Water Acidification ◽  
Interlamellar Water ◽  
Water Ph ◽  
Ph Stat ◽  
Control Water

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.

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