Thyroid function and dermal purines in the brook trout, Salvelinus fontinalis (Mitchill)

1971 ◽  
Vol 49 (12) ◽  
pp. 1557-1561 ◽  
Author(s):  
Dixie Chua ◽  
J. G. Eales
Keyword(s):  
Body Weight ◽  
Thyroid Function ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Thyroxine Treatment

Both TSH and thyroid powder significantly increased skin guanine and hypoxanthine levels over a 5-week period at 15 °C. TSH was more effective than thyroid powder.Injected thyroxine as low as 0.05 μg/g body weight per 2 days and ambient thiourea as low as 0.0001% inhibited thyroid function over 3 weeks at 10 °C. This thyroxine treatment did not significantly increase skin purine levels, but thiourea as low as 0.01% significantly decreased skin hypoxanthine and total purinelevels.

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

Variation of Hepatic Ethoxycoumarin O-de-ethylase Activity with Body Weight and Other Factors in Brook Trout (Salvelinus fontinalis)

1982 ◽  
Vol 39 (6) ◽  
pp. 924-926 ◽  
Author(s):  
R. F. Addison ◽  
D. E. Willis
Keyword(s):  
Body Weight ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Regression Coefficient ◽  
Biological Effects ◽  
Experimental Studies ◽  
Monitoring Program ◽  
Liver Weight ◽  
Microsomal Protein ◽  
Biological Effects Monitoring

Data from several previous experimental studies of hepatic mixed function oxidase (MFO) activity were reexamined to study the possible relationship between ethoxycoumarin O-de-ethylase activity and body weight and other factors in "uninduced" brook trout (Salvelinus fontinalis). Weight-specific O-de-ethylase activity was inversely related to body weight; regression of the log transformation of the total hepatic O-de-ethylase activity on log liver weight yielded a regression coefficient of 0.850 ± 0.047 close to the value of ~0.75 expected for a relationship based on overall metabolic rate. The regression coefficient was significantly higher in males than in females. Multiple regression analysis showed O-de-ethylase activity to be positively correlated with both microsomal protein and cytochrome P-450 content. The data confirm that size (or age) is a factor to be eliminated in any biological effects monitoring program based on MFO assays.Key words: mixed function oxidases, ethoxycoumarin O-de-ethylase, brook trout, Salvelinus fontinalis; hepatic mono-oxygenases

scholarly journals The Effect of Non-Circadian Photoperiod on Growth and Puberty Onset of Brook Trout Salvelinus fontinalis Mitchill

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 692
Author(s):  
Katsiaryna Lundova ◽  
Jan Matousek ◽  
Vlastimil Stejskal
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Somatic Growth ◽  
Continuous Light ◽  
Control Group ◽  
Sexually Mature ◽  
Average Body ◽  
Average Body Weight

The aim of the present study was to assess the effects of a prolonged photoperiod on growth rate and sexual maturation in brook trout Salvelinus fontinalis. The task of the experiment was to determine the most effective light regimen capable to minimizing the effects of puberty, including impairment of somatic growth and further general characteristics. In this regard, the studied fish were reared under three photoperiod regimens in which fish were exposed to 24 h continuous light alternating with 24 or 48 h under the ambient photoperiod or 48 h continuous light alternating with a 24 h ambient photoperiod. A control group was reared under the natural ambient photoperiod. Four-hundred and fifty fish with an average initial body weight of 101.3 ± 1.2 g were used for each experimental group (three replicates of each treatment plus control). A statistically lower growth rate showed control groups in both sexes. At the end of the study, control males had an average body weight of 226.6 ± 39.8 g and control females a body weight of 199.8 ± 12.2 g. At the same period, a significantly higher average body weight was found in groups reared 24 h under ambient photoperiod alternating with a 48 h continuous light regime (2CP:1AP) in both sexes (296.56 ± 62.5 g—males, and 239.9 ± 19.2 g—females, respectively). A significantly higher percentage of sexually mature fish was observed in the control group (80% of males and 29% of females, respectively). We found significantly fewer sexually mature females compared to males. The lowest survival was observed in group 2CP:1AP at 92%. It was concluded that regimen under which fish was exposed to 48 h of natural ambient photoperiod alternating with 24 h of constant light (1CP:2AP) lead to the successful delay of gonad development and onset of puberty and increased somatic growth in both sexes.

Genetic and environmental correlates of variation in body weight of brook trout (Salvelinus fontinalis)

1995 ◽  
Vol 52 (2) ◽  
pp. 307-314 ◽  
Author(s):  
Moira M. Ferguson ◽  
Arunas P. Liskauskas ◽  
Roy G. Danzmann
Keyword(s):  
Body Weight ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Environmental Correlates ◽  
Hatching Time ◽  
First Feeding ◽  
Lake Algonquin ◽  
Nested Designs ◽  
Males And Females ◽  
Provincial Park

Families of brook trout (Salvelinus fontinalis) were produced from adults collected from Mykiss Lake, Algonquin Provincial Park, Ontario, and reared in the laboratory for 1 year. Egg size and hatching time explained a significant amount of variation among families in mean weight of hatched embryos. Heavier embryos were produced from larger eggs, and embryos with earlier hatching times were also larger. First-feeding alevins reared at higher densities were smaller than those at lower densities. Multilocus enzyme heterozygosity was neither a significant predictor of mean family body weight at any age nor significantly associated with body weight of juveniles within families. Analyzing each enzyme locus separately revealed significant effects for G3PDH-1 in two families but in different directions. Fish from two mitochondrial DNA phylogenetic assemblages, A and B, differed significantly in weight as hatched embryos and first-feeding alevins. Similarly, the progeny of different males and females differed significantly in body weight at all ages sampled. Thus, parental effects were the most persistent correlates of body size of all those examined. The statistical analyses and the nested designs suggest that variation in body weight among the progeny of specific parents can partially be attributed to genetic effects.

Parasite-induced susceptibility to predation in diplostomiasis

Parasitology ◽  
1982 ◽  
Vol 85 (3) ◽  
pp. 495-501 ◽  
Author(s):  
P. Brassard ◽  
M. E. Rau ◽  
M. A. Curtis
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Marked Decrease ◽  
Infected Fish ◽  
Induced Susceptibility ◽  
Diplostomum Spathaceum

Guppies (Lebistes reticulatis) exposed to doses as low as 25 cercariae of Diplostomum spathaceum for 30 min were consistently and significantly more susceptible to predation by brook trout (Salvelinus fontinalis) than uninfected controls. The increase in susceptibility to predation was correlated with a marked decrease in the activity of infected fish.

scholarly journals Brook trout passage performance through culverts

2016 ◽  
Vol 73 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Elsa Goerig ◽  
Theodore Castro-Santos ◽  
Normand Émile Bergeron
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Structural Characteristics ◽  
Passive Integrated Transponder ◽  
Complex Interactions ◽  
Factors Influencing ◽  
Several Variables ◽  
And Behavior ◽  
Steep Slopes ◽  
Corrugated Metal

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.

Food Specialization By Individual Trout

1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Cutthroat Trout ◽  
Salmo Gairdneri ◽  
Potential Prey ◽  
Repeated Observation ◽  
Size Growth ◽  
Salmo Clarki

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.

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