Interrenal, Thyroidal, Carbohydrate, and Electrolyte Responses in Rainbow Trout (Salmo gairdneri) during Recovery from the Effects of Acidification

1986 ◽  
Vol 43 (3) ◽  
pp. 714-718 ◽  
Author(s):  
S. B. Brown ◽  
R. E. Evans ◽  
Toshiaki J. Hara
Keyword(s):  
Rainbow Trout ◽  
Sodium Chloride ◽  
Plasma Glucose ◽  
Plasma Cortisol ◽  
Acid Treatment ◽  
Acid Exposure ◽  
Salmo Gairdneri ◽  
Nuclear Diameter ◽  
Fluid Compartment ◽  
Plasma Electrolytes

Exposure to acid-treated water (H2SO4, pH 4.76) for 21 d increased plasma glucose, protein, and cortisol levels and interrenal nuclear diameter and decreased plasma electrolytes (Na+, Cl−) and osmolality in immature rainbow trout (Salmo gairdneri). Plasma L-thyroxine (T4), 3,5,3′-triiodo-L-thyronine (T3), or their ratio (T4:T3) were not altered by the acid treatment. Following termination of acid exposure, return to control levels was achieved within 1 d by plasma protein, 3 d by plasma cortisol, glucose, sodium, chloride, and osmolality, and 7 d by interrenal nuclear diameter. Thus, within 1 wk the studied aspects of the plasma fluid compartment had recovered from the effects of acid exposure.

Effect of Prior Acid Exposure on Physiological Responses of Juvenile Rainbow Trout (Salmo gairdneri) to Acute Handling Stress

1985 ◽  
Vol 42 (4) ◽  
pp. 710-717 ◽  
Author(s):  
Bruce A. Barton ◽  
Gary S. Weirter ◽  
Cars B. Schreck
Keyword(s):  
Rainbow Trout ◽  
Plasma Glucose ◽  
Plasma Cortisol ◽  
Acid Stress ◽  
Peak Level ◽  
Acid Exposure ◽  
Salmo Gairdneri ◽  
Plasma Sodium ◽  
Handling Stress ◽  
Juvenile Rainbow Trout

Acid-stressed fish appear to be more sensitive to additional stressors than unstressed fish. When juvenile rainbow trout, Salmo gairdneri, were exposed to acid conditions (pH 5.7–4.7) for 5 d, plasma cortisol was affected only slightly during the initial hours of exposure, but plasma glucose and hematocrit increased, and plasma sodium decreased. However, when fish held at pH 4.7 were subsequently subjected to a 30-s handling stress, poststress plasma cortisol rose to a peak level of more than twice that in handled fish held at ambient pH (6.6). Effects of handling on plasma glucose or sodium were not apparent against levels already altered by the chronic acid exposure, judging by the corticosteroid response, we conclude that the acid-stressed fish were more sensitive to additional handling, even though they appeared to be physiologically normal after 5 d. Thus, as a management consideration, when fish are stocked in acidified waters, care should be taken to avoid situations where the fish may encounter additional disturbances in the new environment. Plasma glucose and sodium were better indicators of chronic acid stress alone than plasma cortisol, but the greater cortisol response to handling at low pH may be a useful method of detecting increased interrenal activity during early stages of environmental acidification.

Interrenal, Thyroidal, and Carbohydrate Responses of Rainbow Trout (Salmo gairdneri) to Environmental Acidification

1984 ◽  
Vol 41 (1) ◽  
pp. 36-45 ◽  
Author(s):  
S. B. Brown ◽  
J. G. Eales ◽  
R. E. Evans ◽  
Toshiaki J. Hara
Keyword(s):  
Rainbow Trout ◽  
Plasma Glucose ◽  
Plasma Cortisol ◽  
Acid Stress ◽  
Acid Exposure ◽  
Salmo Gairdneri ◽  
Significant Elevation ◽  
Histological Changes ◽  
Treated Fish ◽  
Cortisol Release

Exposure to acid-treated water (H2SO4, pH 6.0–4.2) for 21 d altered interrenal and thyroid function in immature rainbow trout, Salmo gairdneri. At a pH < 5.2 plasma Cortisol increased, implying sustained interrenai Cortisol release. Interrenal histology showed hyperplasia and elevated nuclear diameter at pH 4.7. Eight days of acid exposure (pH 4.7) were required to raise plasma Cortisol significantly. At a pH < 4.7 the ratio of plasma T4 (L-thyroxine) to T3 (3,5,3′-triiodo-L-thyronine) tended to increase in relation to the controls. Depending on the experiment, this was due to either a significant elevation in plasma T4 or a decrease in plasma T3. No histological changes were evident in the thyroid of acid-treated trout. Eight days of acid exposure (pH 4.7) were required to depress plasma T3. Coincidental with higher interrenal activity, plasma glucose was elevated in acid-treated fish (pH < 5.2) after 4 d of exposure. The possible relationships of the endocrinde changes to accompanying acid-induced elevations in plasma glucose and protein and hepatocyte histochemistry are considered, and their possible roles as indices of acid stress are discussed.

DIFFERENCES IN CONCENTRATIONS OF PLASMA CORTISOL IN THE TROUT AND THE EEL FOLLOWING ADAPTATION TO BLACK OR WHITE BACKGROUNDS

1981 ◽  
Vol 89 (1) ◽  
pp. 135-140 ◽  
Author(s):  
BRIDGET I. BAKER ◽  
THERESA A. RANCE
Keyword(s):  
Rainbow Trout ◽  
Plasma Cortisol ◽  
Binding Capacity ◽  
Anguilla Anguilla ◽  
Short Photoperiod ◽  
Salmo Gairdneri ◽  
Pars Intermedia ◽  
Total Cortisol ◽  
The Difference ◽  
Long Photoperiod

When rainbow trout (Salmo gairdneri) and eels (Anguilla anguilla) were kept in black tanks for 3—4 weeks, their plasma cortisol titres were about fourfold higher than in fish kept in white tanks. In trout, the difference was apparent only under a long photoperiod of 16 h light: 8 h darkness, but in eels the difference was clear under both a long or short photoperiod (9·5 h light: 14·5 h darkness). It is suggested that the increase in plasma cortisol seen in black-adapted fish is dependent on either ACTH or MSH secreted by the pars intermedia melanotrophs. No difference was seen either in the total cortisol-binding capacity of the plasma nor in interrenal histology in trout from black or white backgrounds.

Long-Term Sublethal Acid Exposure in Rainbow Trout (Salmo gairdneri) in Soft Water: Effects on Ion Exchanges and Blood Chemistry

1988 ◽  
Vol 45 (8) ◽  
pp. 1387-1398 ◽  
Author(s):  
Céline Audet ◽  
R. Stephen Munger ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
Ammonia Excretion ◽  
Blood Chemistry ◽  
Soft Water ◽  
Acid Exposure ◽  
Salmo Gairdneri ◽  
Plasma Parameters ◽  
Water Effects ◽  
Net Flux

Long-term sublethal acid exposure (3 mo, pH 4.8) in adult rainbow trout (Salmo gairdneri) acclimated to artificial soft water (Ca2+ = 50, Na+ = 50, Cl− = 100 μeq∙L−1) caused transient net fosses of Na+ and Cl−. Net flux rates of both ions were returned to control levels after 30–52 d of acid exposure through a new equilibrium between unidirectional influx and efflux, where both were lower than control rates. K+ balance remained negative and Ca2+ balance at zero throughout the exposure. No changes in net acidic equivalent flux occurred, indicating the absence of acid–base disturbance, but ammonia excretion increased over time. Muscle K+, Na+, and Cl− fell and Ca2+ increased. Plasma Na+, Cl−, and osmolality decreased, while plasma protein, glucose, and blood hemoglobin increased during the first few weeks of acid exposure. Plasma K+ and Ca2+ did not change. General stabilization of plasma parameters occurred in concert with the stabilization of Na+ and Cl− flux rates, but no recovery to control levels was observed for any of them. We conclude that despite this stabilization at a new steady state, rainbow trout were physiologically affected in a deleterious manner by chronic sublethal acid exposure in soft water.

Effect of Shock Exposures of Chlorine on the Plasma Electrolyte Concentrations of Adult Rainbow Trout (Salmo gairdneri)

1977 ◽  
Vol 34 (7) ◽  
pp. 1034-1039 ◽  
Author(s):  
Ibrahim H. Zeitoun ◽  
Leroy D. Hughes ◽  
Duane E. Ullrey
Keyword(s):  
Rainbow Trout ◽  
Plasma Concentrations ◽  
Water Environment ◽  
Retention Mechanism ◽  
Salmo Gairdneri ◽  
Plasma Electrolyte ◽  
Fish Blood ◽  
Plasma Electrolytes ◽  
Test Fish ◽  
Copper Zinc

Blood was pooled from randomly selected 3-yr-old rainbow trout (Salmo gairdneri) before addition of chlorine to their water environment and afterward when fish began to gulp for air and lose equilibrium. In five duplicate tests, plasma concentrations of phosphorus, magnesium, iron, copper, zinc, and potassium increased substantially in the stressed fish. Calcium concentration was also higher, but not significantly so in the plasma of the test fish as compared with those of the controls. Sodium was the only electrolyte that dropped substantially (P < 0.01) in the test fish as compared with the controls.Chlorine toxicity appeared to disturb the mineral homeostasis in the fish blood. Rapid recruitment of electrolytes from the environment and movement into the plasma, a strong mineral retention mechanism, or mobilization of body mineral stores worked together or individually to compensate for those minerals lost with water during hemoconcentration. Key words: rainbow trout, plasma electrolytes, chlorine, hemolysis, hematology, toxicology

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