Do Rainbow Trout (Salmo gairdneri) Acclimate to Low pH?

1988 ◽  
Vol 45 (8) ◽  
pp. 1399-1405 ◽  
Author(s):  
Céline Audet ◽  
Chris M. Wood
Keyword(s):  
Rainbow Trout ◽  
High Stress ◽  
Acid Stress ◽  
Ammonia Excretion ◽  
Acid Exposure ◽  
Cell Swelling ◽  
Whole Body ◽  
Salmo Gairdneri ◽  
Base Exchange

Adult rainbow trout (Salmo gairdneri) previously exposed to long-term sublethal acid stress (3 mo, pH 4.8) in artificial soft water (Ca2+ = 50, Na+ = 50, Cl− = 100 μeq∙L−1) were challenged with acute severe acid exposure (4.5–5 h, pH 4.0). Their response in terms of whole-body ionic exchanges and blood chemistry was compared with that of trout that had no previous history of acid exposure (naive fish). Acute pH 4.0 exposure caused significant ionoregulatory disturbances in both acid-preexposed and naive fish. Rates of net Na+ and Cl− body losses were twice as large in acid-preexposed fish as in naive fish. The two groups showed similar slight net uptake of acidic equivalents. However, the dynamics of acid–base exchange differed, especially with regard to ammonia excretion which was elevated in acid-preexposed fish and inhibited in naive fish. A larger decrease in plasma Na+, red blood cell swelling, and the maintenance of high-stress indicators (elevated plasma glucose and ammonia excretion, depressed osmolality) confirmed that osmo-ionoregulatory disturbances were more intense in acid-preexposed fish than in naive fish. Thus, long-term sublethal acid exposure did not improve but rather significantly decreased the ability of rainbow trout to respond to more severe acid stress. We conclude that acclimation to acid stress does not occur in rainbow trout.

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 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.

Long-term effects of arsenic accumulation in rainbow trout,Salmo gairdneri

1984 ◽  
Vol 32 (1) ◽  
pp. 732-741 ◽  
Author(s):  
A. A. Oladimeji ◽  
S. U. Qadri ◽  
A. S. W. deFreitas
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Long Term Effects ◽  
Arsenic Accumulation

Induction of metallothionein synthesis in rainbow trout,Salmo gairdneri, during long-term exposure to waterborne cadmium

1989 ◽  
Vol 6 (4) ◽  
pp. 221-229 ◽  
Author(s):  
Per-Erik Olsson ◽  
Åke Larsson ◽  
Amund Maage ◽  
Carl Haux ◽  
Keith Bonham ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Waterborne Cadmium

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.

Acute Ammonia Toxicity and Ammonia Excretion in Rainbow Trout (Salmo gairdneri)

1979 ◽  
Vol 36 (6) ◽  
pp. 621-629 ◽  
Author(s):  
Betty A. Hillaby ◽  
David J. Randall
Keyword(s):  
Rainbow Trout ◽  
Ammonia Excretion ◽  
Hydrogen Ion ◽  
Ammonia Toxicity ◽  
Salmo Gairdneri ◽  
Mean Values ◽  
Arterial Blood ◽  
Blood Ph ◽  
Before And After ◽  
Total Ammonia

Acute ammonia toxicity in rainbow trout (Salmo gairdneri) was studied by intraarterial injection of NH4Cl and NH4HCO3. Hydrogen ion and total ammonia concentrations were measured in blood sampled from the dorsal aorta both before and after injection. Although injection of NH4HCO3 increased arterial blood pH, and injection of NH4Cl decreased arterial blood pH, the same dose of each was required to kill fish. While the un-ionized form of ammonia in water has been shown to be toxic, in the blood either the ionized form or the total ammonia load is toxic to fish. Ammonia levels were measured in pre- and postbranchial blood. Mean values were not significantly different, but paired values indicated a fall in blood ammonia due to excretion across the gills. There appears to be a more rapid excretion of ammonia following NH4HCO3 infusions, which result in higher un-ionized ammonia levels in blood compared with those following NH4Cl infusions. These results are consistent with the hypothesis that ammonia is excreted in the un-ionized form. Key words: un-ionized ammonia, ionized ammonia, gills, pH, blood

Models of Ammonia Excretion for Brook Trout (Salvelinus fontinalis) and Rainbow Trout (Salmo gairdneri)

1980 ◽  
Vol 37 (9) ◽  
pp. 1421-1425 ◽  
Author(s):  
Larry J. Paulson
Keyword(s):  
Body Weight ◽  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Ammonia Excretion ◽  
Salmo Gairdneri ◽  
Feeding Rates ◽  
Data Set ◽  
Nitrogen Consumption ◽  
Good Agreement

Ammonia excretion by brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri) was measured in relation to nitrogen consumption, body weight (15–154 g for rainbow trout and 50–360 g for brook trout), and temperature (11.2–21.0 °C) under laboratory conditions. Four natural diets, collected from Castle Lake, California, and a commercial pellet diet were fed to the trout in gelatin capsules at feeding rates from 2.5 to 5% body weight∙d−1. Nitrogen consumption was the most important factor influencing ammonia excretion, followed by body weight and temperature. Testing the models with an independent data set revealed good agreement between measured and predicted rates of excretion. The models seem to estimate adequately ammonia excretion by trout in both natural and artificial aquatic systems.Key words: models, ammonia excretion, nitrogen consumption, body weight, temperature, multiple regression, rainbow trout, brook trout

A respirometric analysis of fuel use during aerobic swimming at different temperatures in rainbow trout (Oncorhynchus mykiss)

1998 ◽  
Vol 201 (22) ◽  
pp. 3123-3133 ◽  
Author(s):  
JD Kieffer ◽  
D Alsop ◽  
CM Wood
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Swimming Speed ◽  
Ammonia Excretion ◽  
Whole Body ◽  
Acclimation Temperature ◽  
Fish Swimming ◽  
Fuel Use ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Absolute Basis

Instantaneous fuel usage at 5 degreesC or 15 degreesC was assessed by measurement of rates of O2 consumption (O2), CO2 excretion (CO2) and nitrogenous waste excretion (nitrogen =ammonia-N + urea-N) in juvenile rainbow trout (Oncorhynchus mykiss) at rest and during swimming at 45 % and 75 % of aerobic capacity (Ucrit). After 2 weeks of training at approximately 1 body length s-1 (BL s-1), critical swimming speeds (approximately 3.0 BL s-1) and whole-body energy stores (total protein, lipids and carbohydrates) were identical in fish acclimated to 5 degreesC or 15 degreesC. O2 and CO2 increased with swimming speed at both temperatures and were higher at 15 degreesC than at 5 degreesC at all speeds, but the overall Q10 values (1.23-1.48) were low in these long-term (6 weeks) acclimated fish. The respiratory quotient (CO2/O2, approximately 0.85) was independent of both temperature and swimming speed. In contrast to O2 and CO2, the rate of ammonia excretion was independent of swimming speed, but more strongly influenced by temperature (Q10 1. 4-2.8). Urea excretion accounted for 15-20 % of nitrogen, was unaffected by swimming speed and showed a tendency (P&lt;0.07) to be positively influenced by temperature at one speed only (45 % Ucrit). Nitrogen quotients (NQ nitrogen/O2) were generally higher in warm-acclimated fish, remaining independent of swimming speed at 15 degreesC (0.08), but decreased from about 0.08 at rest to 0.04 during swimming at 5 degreesC. Instantaneous aerobic fuel use calculations based on standard respirometric theory showed that both acclimation temperature and swimming speed markedly influenced the relative and absolute use of carbohydrates, lipids and proteins by trout. At rest, cold-acclimated trout used similar proportions of carbohydrates and lipids and only 27 % protein. During swimming, protein use decreased to 15 % at both speeds while the relative contributions of both lipid and carbohydrate increased (to more than 40 %). On an absolute basis, carbohydrate was the most important fuel for fish swimming at 5 degreesC. In contrast, resting fish acclimated to 15 degreesC utilized 55 % lipid, 30 % protein and only 15 % carbohydrate. However, as swimming speed increased, the relative contribution of carbohydrate increased to 25 %, while the protein contribution remained unchanged at approximately 30 %, and lipid use decreased slightly (to 45 %). On an absolute basis, lipid remained the most important fuel in fish swimming at 15 degreesC. These results support the concept that lipids are a major fuel of aerobic exercise in fish, but demonstrate that the contribution of protein oxidation is much smaller than commonly believed, while that of carbohydrate oxidation is much larger, especially at higher swimming speeds and colder temperature.

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