Elevated Levels of Arginine Vasotocin in the Brain of Brook Trout (Salvelinus fontinalis) from Acid Lakes: A Field Test of a Potential Biomarker for Acid Stress

1993 ◽  
Vol 50 (8) ◽  
pp. 1717-1727 ◽  
Author(s):  
A. Hontela ◽  
J. B. Rasmussen ◽  
K. Lederis ◽  
H. V. Tra ◽  
G. Chevalier
Keyword(s):  
Body Size ◽  
Field Test ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Acid Stress ◽  
Low Ph ◽  
Arginine Vasotocin ◽  
Potential Biomarker ◽  
Different Seasons ◽  
The Relationship

The levels of arginine vasotocin (AVT), an osmoregulatory peptide, were determined by radioimmunoassay in brain tissue of brook trout (Salvelinus fontinalis) of a wide size range (50–380 mm) from softwater Laurentian lakes ranging in pH from 5.0 to 6.9 at different seasons. Multivariate models (ANCOVA) were developed to quantify the relationship between AVT, pH, body size, and season. Brain AVT levels increased with body size, and the allometric slope was highest in the low-pH lakes (pH 5.0-5.5). Although brook trout > 150 mm had higher brain AVT levels at low pH, no significant differences were detected for brook trout < 150 mm. We hypothesize that the sensitivity of brook trout at the parr stage to acid stress may be linked to their inability to mobilize a hormonal response involving AVT. The seasonal variation in brain AVT levels was similar in all the lakes studied, summer levels being the highest. Although this field study revealed that AVT levels depend also on factors other than acid stress (body size and season), our ANCOVA models allow adjustment for the effects of these covariables. Analyses of this type can be used to field test and calibrate biomarkers for use in ecotoxicology.

Arginine Vasotocin, an Osmoregulatory Hormone, as a Potential Indicator of Acid Stress in Fish

1991 ◽  
Vol 48 (2) ◽  
pp. 238-242 ◽  
Author(s):  
A. Hontela ◽  
J. B. Rasmussen ◽  
D. Ko ◽  
K. Lederis ◽  
G. Chevalier
Keyword(s):  
Early Warning ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Acid Stress ◽  
Arginine Vasotocin ◽  
Lower Plasma ◽  
Demineralized Water ◽  
Early Warning Indicators ◽  
Potential Indicator ◽  
Warning Indicators

Brook trout (Salvelinus fontinalis) exposed for 1 wk to pH 5.6 (sublethal acidity) exhibited higher forebrain and pituitary arginine vasotocin (AVT) levels and lower plasma Na+ levels than fish exposed to pH 6.7 (control). Addition of 300 μg total Al/L to water at pH 5.6 did not augment the effect on either the plasma Na+ or the AVT levels. Exposure to demineralized water for 1 wk lowered the plasma Na+ and increased AVT in the forebrain but had no effect on pituitary AVT. The increased AVT levels could be used as early warning indicators of sublethal acid stress in the brook trout. Such indicators, used in wild fish, might become important tools in management of trout lakes in areas threatened by acidification.

Sodium Transport In the Brook Trout, Salvelinus fontinalis: Effects of Prolonged Low pH Exposure in the Presence and Absence of Aluminum

1988 ◽  
Vol 45 (9) ◽  
pp. 1606-1613 ◽  
Author(s):  
D. G. McDonald ◽  
C. L. Millsgan
Keyword(s):  
Linear Model ◽  
Sodium Transport ◽  
Brook Trout ◽  
Prolonged Exposure ◽  
Salvelinus Fontinalis ◽  
Low Ph ◽  
Compensatory Mechanism ◽  
Transport Activity ◽  
Presence And Absence ◽  
The Relationship

This study examined the effects of prolonged exposure [Formula: see text] to low Ca2+ (25 versus 400 μequiv/L), low pH (pH 5.2 versus 6.5) with and without Al (150 μg/L) on Na+ uptake in adult brook trout (Salvelinus fontinalis). Na+ uptake (JinNa+) was assessed by measuring radiotracer disappearance from the medium at ambient Na+ (79 μequiv/L) and in response to acute increases in ambient Na+. The relationship between JinNa+ and [Na+] was best described by a linear model with the slope of the line a measure of transport activity. Transport activity increased as a result of prolonged low Ca2+ exposure at pH 6.5, but declined in fish maintained at pH 5.2. These fish showed no compensation in response to low pH; there was no recovery in transport activity when pH was acutely raised to 6.5, and lower pH's further inhibited uptake. In contrast, the Na+ transport activity of fish maintained at pH 5.2 and 150 μg Al/L was significantly greater than that of fish acclimated to pH 5.2 alone and indeed greater than pH 6.5 controls. This indicates that Al exposure induced a compensatory mechanism in the gills that was not seen with low pH exposure alone.

Retardation and Recovery of Growth in Brook Trout Fry (Salvelinus fontinalis) Exposed for Various Durations to Acidified Water

1986 ◽  
Vol 43 (10) ◽  
pp. 2048-2050 ◽  
Author(s):  
W. H. Tam ◽  
P. D. Payson ◽  
R. J. J. Roy
Keyword(s):  
Growth Inhibition ◽  
Growth Rates ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Low Ph ◽  
Fish Growth ◽  
Control Fish ◽  
Treated Fish ◽  
Test Fish ◽  
Neutral Water

Brook trout fry (Salvelinus fontinalis) were exposed to pH 4.66 for various durations up to 141 d and then returned to neutral water. Growth of test fish was in general significantly lower than that of control fish for exposures up to days 45–78. In four of six groups of acid-treated fish, growth eventually recovered and the growth rates were not different from that of control fish. The results suggested that growth inhibition was induced early in the exposure to sublethally low pH and that recovery in the latter phase of the experiment occurred whether pH remained acidic or was readjusted to neutral.

Ambient pH and Calcium Concentration as Modifiers of Growth and Calcium Dynamics of Brook Trout, Salvelinus fontinalis

1984 ◽  
Vol 41 (12) ◽  
pp. 1774-1780 ◽  
Author(s):  
David W. Rodgers
Keyword(s):  
Brook Trout ◽  
Calcium Concentration ◽  
Salvelinus Fontinalis ◽  
Axial Skeleton ◽  
Low Ph ◽  
Fish Growth ◽  
Calcium Dynamics ◽  
Experimental Fish ◽  
Low Calcium ◽  
High Calcium

Juvenile brook trout, Salvelinus fontinalis, were maintained in water of pH 5.3 or 6.5 and calcium concentrations of 5 or 40 mg/L to determine the effects of these factors on fish growth and calcium dynamics. Growth rates varied more than twofold and were significantly reduced by both low ambient calcium concentration and low pH. In contrast, calcium dynamics of the fish were significantly affected by calcium concentration but not pH. Brook trout in low-calcium water retained less labeled dietary calcium and deposited less labeled calcium in axial skeleton and visceral tissues than fish in high-calcium water. Calcium concentrations of the skin and fins were slightly but significantly reduced among fish in low-calcium water, but neither pH nor ambient calcium concentration significantly affected ash content or calcium concentration of axial skeleton and visceral tissues of experimental fish.

Effects of Aluminum and Low pH on Net Ion Fluxes and Ion Balance in the Brook Trout (Salvelinus fontinalis)

1988 ◽  
Vol 45 (9) ◽  
pp. 1563-1574 ◽  
Author(s):  
C. E. Booth ◽  
D. G. McDonald ◽  
B. P. Simons ◽  
C. M. Wood
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Inhibitory Effect ◽  
Low Ph ◽  
Exposed Fish ◽  
Water Ph ◽  
In The Wild ◽  
Ph Dependent ◽  
Total Body ◽  
Stimulation Of

Adult brook trout (Salvelinus fontinalis) were exposed for up to 11 d to one of a matrix of 18 Al, low pH, and Ca2+ combinations, chosen as representive of acidified softwater environments in the wild. Reduction in water pH led to pH-dependent net losses of Na+ and Cl− exacerbated by the presence of Al in the water and reduced by elevating Ca2+. Any animal losing more than 4% of its total body Na+ over the first 24 h of Al exposure had a greater than 90% likelihood of eventual mortality. Na+ losses arose from inhibition of influx and stimulation of efflux. The inhibition was persistent and pH dependent. Addition of Al to acidified water had a slight further inhibitory effect on Na+ influx and a large stimulatory effect on efflux. The latter was dependent on Al concentration, was the main cause of initial ion losses and mortality, and declined with time in surviving animals. All Al-exposed fish accumulated Al on their gills, but this was apparently mainly surface or subsurface bound, since no internal Al (plasma or liver) could be detected. Nonsurviving fish had substantially higher gill Al levels than survivors.

scholarly journals Effective number of breeders, effective population size and their relationship with census size in an iteroparous species, Salvelinus fontinalis

2016 ◽  
Vol 283 (1823) ◽  
pp. 20152601 ◽  
Author(s):  
Daniel E. Ruzzante ◽  
Gregory R. McCracken ◽  
Samantha Parmelee ◽  
Kristen Hill ◽  
Amelia Corrigan ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Brook Trout ◽  
Overlapping Generations ◽  
Salvelinus Fontinalis ◽  
Effective Number ◽  
Effective Number Of Breeders ◽  
Unbiased Estimates ◽  
Census Population Size ◽  
The Relationship

The relationship between the effective number of breeders ( N b ) and the generational effective size ( N e ) has rarely been examined empirically in species with overlapping generations and iteroparity. Based on a suite of 11 microsatellite markers, we examine the relationship between N b , N e and census population size ( N c ) in 14 brook trout ( Salvelinus fontinalis ) populations inhabiting 12 small streams in Nova Scotia and sampled at least twice between 2009 and 2015. Unbiased estimates of N b obtained with individuals of a single cohort, adjusted on the basis of age at first maturation ( α ) and adult lifespan (AL), were from 1.66 to 0.24 times the average estimates of N e obtained with random samples of individuals of mixed ages (i.e. ). In turn, these differences led to adjusted N e estimates that were from nearly five to 0.7 times the estimates derived from mixed-aged individuals. These differences translate into the same range of variation in the ratio of effective to census population size within populations. Adopting as the more precise and unbiased estimates, we found that these brook trout populations differ markedly in their effective to census population sizes (range approx. 0.3 to approx. 0.01). Using A ge N e , we then showed that the variance in reproductive success or reproductive skew varied among populations by a factor of 40, from V k / k ≈ 5 to 200. These results suggest wide differences in population dynamics, probably resulting from differences in productivity affecting the intensity of competition for access to mates or redds, and thus reproductive skew. Understanding the relationship between N e , N b and N c , and how these relate to population dynamics and fluctuations in population size, are important for the design of robust conservation strategies in small populations with overlapping generations and iteroparity.

Plasma electrolytes, gill aluminum content, and gill morphology of juvenile Atlantic salmon (Salmo salar) and brook trout (Salvelinus fontinalis) indigenous to acidic streams of Nova Scotia

1990 ◽  
Vol 68 (6) ◽  
pp. 1270-1280 ◽  
Author(s):  
G. L. Lacroix ◽  
D. J. Hood ◽  
C. S. Belfry ◽  
T. G. Rand
Keyword(s):  
Nova Scotia ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Low Ph ◽  
Secondary Lamellae ◽  
Exchangeable Al ◽  
Plasma Electrolytes ◽  
Gill Morphology

Plasma electrolytes and gill [Al] were determined and gill morphology and histology were examined in Atlantic salmon (Salmo salar) parr and brook trout (Salvelinus fontinalis) from feral populations in acidic streams of southwest Nova Scotia. Plasma [Na+] and [Cl−] were lowest in fish from streams with the lowest pH levels, but there were no correlations between plasma [Na+] or [Cl−] and exchangeable [Al] in streams for both species. Gill [Al] increased exponentially with increasing exchangeable [Al] in water, but was less than 100 μg/g dry weight in both species. There were no correlations between plasma [Na+] or [Cl−] and gill [Al] for both species, and plasma [Na+] and [Cl−] were ultimately linked to low pH. Scanning electron microscopy of gills showed normal primary and secondary lamellae, with few signs of fusion or hyperplasia, only a slight amount of mucus, regular chloride cell crypts, and epithelial cells with distinct microridges. Histology of gill sections showed few lesions in the primary lamellae but some focal histologic lesions in the secondary lamellae of greater than 50% of fish, regardless of ambient pH or [Al]. The histopathology included hypertrophy of individual epithelial, mucous, and chloride cells, clubbing of tips of secondary lamellae, and localized epithelial hyperplasia. These features were focal and not comparable to the extensive morphological changes or histologic lesions usually attributed to high [Al] at low pH. Dissolved organic carbon concentrations greater than 5 mg/L in the acidic streams apparently afforded protection against Al effects at concentrations of at least 360 μg total Al/L.

Aluminum and Acid Toxicity to Two Strains of Brook Trout (Salvelinus fontinalis)

1990 ◽  
Vol 47 (8) ◽  
pp. 1641-1648 ◽  
Author(s):  
C G. Ingersoll ◽  
D. D. Gulley ◽  
D. R. Mount ◽  
M. E. Mueller ◽  
J. D. Fernandez ◽  
...  
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Low Ph ◽  
Chloride Cells ◽  
Free Swimming ◽  
Field Exposure ◽  
Fish Weight ◽  
Gill Histology ◽  
Acid Toxicity

Two strains of 1 yr-old brook trout were exposed to 14 combinations of pH, aluminum, and calcium during a 28-d experiment. Survival, weight, and gill histology of both strains were affected similarly by pH, aluminum, and calcium exposure. Survival was reduced at inorganic monomeric aluminum concentrations (IA1) of 29 μg/L at pH 5.2 and [Formula: see text] at pH 4.4 and 4.8. Fish weight was reduced with exposure to pH below 4.8 or aluminum concentrations [Formula: see text]. The gills sampled from fish exposed to low pH exhibited lifting of the outer epithelium and hypertrophy (increase in size) of chloride and epithelial cells. The response of gills sampled from fish exposed to low pH and elevated aluminum was more pronounced relative to the low pH exposure alone. In addition to the effects observed in the low pH exposed fish, the gills from fish exposed to both acid and aluminum exhibited vacuolation and degeneration of epithelial and chloride cells and the presence of dense cells. Finally, fish confined in PVC tubes designed to mimic in situ field exposure procedures were more sensitive to the toxic effects of acid and aluminum compared to free-swimming fish. Caution must be taken when extrapolating safe field levels from in situ exposures of caged fish.

Effect of Long-Term Exposure to Acidf Aluminum, and Low Calcium on Adult Brook Trout (Salvelinus fontimlis). 2. Vitellogenesss and Osmoregulation

1988 ◽  
Vol 45 (9) ◽  
pp. 1633-1642 ◽  
Author(s):  
D. R. Mount ◽  
J. R. Hockett ◽  
W. A. Gern
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Plasma Osmolality ◽  
Low Ph ◽  
Reproductive Physiology ◽  
Treatment Conditions ◽  
Plasma Estradiol ◽  
Survival And Growth ◽  
All Treatment

Adult brook trout (Salvelinus fontinalis) were exposed for 193 d (previtellogenesis to spawning) to six combinations of acid, Al, and low Ca. Survival and growth were reduced by low pH combined with low Ca concentrations. After 41 d of exposure, fish in ail low pH exposures showed depressed plasma osmolality and Na concentrations, but by day 97 this apparent osmoregulatory stress was compensated for in all but the most severe treatment (pH 4.97, 47 μg inorganic Al/L, 0.5 mg Ca/L). At the observed peak of yolking (day 147), fish exposed to this treatment also had mean concentrations of plasma estradiol, vitellogenin, and Ca of only half control values. Fecundity (eggs per female) was significantly reduced as well, but this reduction was due in part to decreased growth. Despite these abnormalities in ionoregulatory and reproductive physiology, fish in all treatment conditions produced mature eggs. Among fish in stressful conditions, individual variation in growth and physiological parameters appeared to be correlated with osmoregulatory status. We hypothesize that the suite of physiological disturbances observed are linked to osmoregulatory impairment.

Downstream Movement and Mortality of Brook Trout (Salvelinus fontinalis) Exposed to Acidic Episodes in Streams

1994 ◽  
Vol 51 (7) ◽  
pp. 1620-1628 ◽  
Author(s):  
Charles J. Gagen ◽  
William E. Sharpe ◽  
Robert F. Carline
Keyword(s):  
Adverse Effects ◽  
Water Samples ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Low Ph ◽  
Stream Discharge ◽  
Individual Fish ◽  
Dead Fish ◽  
Lower Stream ◽  
Downstream Movement

Episodes of low pH and high Al concentration were associated with net downstream movement and increased mortality of ratio-tagged brook trout (Salvelinus fontinalis). We compared movements of 10–15 brook trout in two streams with severe acidic episodes with movements of fish in two streams with less severe acidic episodes (reference streams). Study populations moved downstream hundreds of metres in the streams with more severe acidic episodes (pH <5.0 and >200 μg Al/L). Median downstream movement in spring was 250 and 900 m after 20 d for fish in the more acidic streams; one third of the fish were found dead during this time. We found no net movement and no dead fish in the reference streams. Lower stream discharge in fall studies was associated with less severe acidic episodes, less net movement, and no mortality. Water samples collected at individual fish locations indicated that few fish avoided adverse effects of acidic episodes by remaining in microhabitats with higher pH and lower Al concentration.

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