Genetic Variation and Fitness: A Test in a Naturalized Population of Brook Trout (Salvelinus fontinalis)

1991 ◽  
Vol 48 (11) ◽  
pp. 2152-2162 ◽  
Author(s):  
Arunas P. Liskauskas ◽  
Moira M. Ferguson
Keyword(s):  
Brook Trout ◽  
Sexual Maturity ◽  
Salvelinus Fontinalis ◽  
Positive Association ◽  
Somatic Tissue ◽  
Age Classes ◽  
Life History Stages ◽  
Young Of The Year ◽  
The Relationship ◽  
Provincial Park

The relationship between enzyme heterozygosity and several components of fitness (size and survival) was examined in a naturalized population of brook trout (Salvelinus fontinalis) from Algonquin Provincial Park, Ontario. Significant differences in allele frequency and the number of heterozygous loci per individual were found among five age classes spanning most of the life history stages of brook trout in this population. A young of the year (YOY) cohort sampled after a period of high natural mortality had significantly greater numbers of heterozygous loci per individual than YOY sampled shortly after emergence from redd sites. A positive association between heterozygosity and size was only found in YOY sampled in June and not in the other age classes in which sexual maturity was not a complicating factor. The association between heterozygosity and size was affected by the onset of sexual maturity. Significant negative regressions between multilocus or single locus heterozygosity and size were found in mature males whereas heterozygosity was positively associated with size in females. These dissimilarities may be the result of differences in growth rates prior to sexual maturation and differential allocation of energy towards gametic and somatic tissue.

Brook Trout (Salvelinus fontinalis) Population Structure in Acidified Lac Tantaré, Quebec

1984 ◽  
Vol 41 (6) ◽  
pp. 865-877 ◽  
Author(s):  
Jean-Jacques Frenette ◽  
Julian J. Dodson
Keyword(s):  
Population Structure ◽  
Brook Trout ◽  
Sexual Maturity ◽  
Reproductive Effort ◽  
Salvelinus Fontinalis ◽  
Individual Growth ◽  
Toxic Stress ◽  
Age Classes ◽  
Recruitment Failure ◽  
Trout Population

To present evidence of acid-induced stress, we studied the population structure and distribution of brook trout (Salvelinus fontinalis) in acidified Lac Tantaré, Quebec. Trout greater than 21 cm (FL) represented only 16.2 and 10% of the population sampled in 1979 and 1980, respectively. Survival rates of trout from 1979 to 1980 indicated higher survival among individuals > 25 cm, mortality occurring primarily among fish of 13–25 cm. The marked decline in numbers of fish occurring at 21 cm coincided with the size at which 50% of the female trout population reached sexual maturity, suggesting that postspawning mortality contributes to the high mortality observed among these fish. Comparisons of population and individual growth rates revealed that smaller fish of age-classes 1 to 5 suffer higher mortality than do the larger individuals of these age-classes, implicating mortality agents other than those related to spawning. We provide evidence to support the hypothesis that the most probable cause of mortality is size-related differential exposure to toxic stress whereby small brook trout (< 25 cm) are found in lake areas (brooks) exhibiting the most potentially toxic combination of pH and aluminum, thus enhancing the exposure of the most susceptible part of the population to toxic stress. Large brook trout [Formula: see text] are found in the "safest" lake areas (springs), thus diminishing the exposure of the least susceptible part of the population to toxic stress and enhancing survival. Female trout exhibit delayed sexual maturity relative to other Quebec populations, attaining 50% maturity at age 3 and a length of 21–24 cm such that the major part of the population's reproductive effort is provided by those fish representing only 15% of the population in 1979 and 1980. During the October spawning season, 20% of potential spawners exhibited retarded oogenesis. These reductions in reproductive effort and changes in spawning site selection provide evidence in support of the hypothesis that recruitment failure may be occurring in the Tantaré brook trout population.

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.

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.

Differences in sexual maturity and fall emigration between diploid and triploid brook trout (Salvelinus fontinalis) in an Adirondack lake

1997 ◽  
Vol 54 (8) ◽  
pp. 1808-1812 ◽  
Author(s):  
J.A. Warrillow ◽  
D.C. Josephson ◽  
W.D. Youngs ◽  
C.C. Krueger
Keyword(s):  
Brook Trout ◽  
Sexual Maturity ◽  
Salvelinus Fontinalis

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.

THE STRUCTURE AND DEVELOPMENT OF THE EXTERNAL MEMBRANE IN YOUNG EGGS OF THE BROOK TROUT, SALVELINUS FONTINALIS (MITCHILL)

1966 ◽  
Vol 44 (2) ◽  
pp. 173-190 ◽  
Author(s):  
Donal A. Hurley ◽  
Kenneth C. Fisher
Keyword(s):  
Electron Microscopy ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Morphological Changes ◽  
The Other ◽  
Follicular Cells ◽  
Immature Oocytes ◽  
Zona Radiata ◽  
Pore Canals ◽  
The Relationship

A study of the external membranes of the developing oocyte of the brook trout, Salvelinus fontinalis, was made by means of electron microscopy. The membrane, zona radiata, which becomes "hardened" in mature eggs after they are shed into water, was observed to begin development at the bases of microvilli which project from the surface of the oocyte. This membrane grows until in the mature egg it is about 50 μ thick. The zona radiata is completely permeated by numerous pore canals. In immature oocytes, the pore canals contain microvilli which arise from the surface of the oocyte. The microvilli make contact with the follicular cells surrounding the developing oocyte. Morphological changes which occur in the zona radiata and the other layers of developing oocytes are described at several stages of development. The relationship between morphological changes in the membranes and the transport of nutrients to the developing oocyte is discussed.The nomenclature of the membranes of the mature trout egg is discussed in relation to the findings of the present study. It is concluded that primary membranes and perhaps secondary membranes are present in the mature trout egg.

Breaking the speed limit — comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)

2013 ◽  
Vol 70 (2) ◽  
pp. 280-293 ◽  
Author(s):  
Theodore Castro-Santos ◽  
Francisco Javier Sanz-Ronda ◽  
Jorge Ruiz-Legazpi
Keyword(s):  
Brown Trout ◽  
Brook Trout ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Swimming Performance ◽  
Physiological Limits ◽  
Brown Trout Salmo Trutta ◽  
Free Ranging ◽  
The Relationship ◽  
Sprint Swimming

Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

Effects of maternal stress and cortisol exposure at the egg stage on learning, boldness and neophobia in brook trout

Behaviour ◽  
2016 ◽  
Vol 153 (13-14) ◽  
pp. 1639-1663 ◽  
Author(s):  
Sergio Cortez Ghio ◽  
Antoine Boudreau Leblanc ◽  
Céline Audet ◽  
Nadia Aubin-Horth
Keyword(s):  
Spatial Learning ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Maternal Stress ◽  
Maternal Plasma ◽  
Spatial Learning And Memory ◽  
Maternal Factors ◽  
Species Specific ◽  
Brook Char ◽  
The Relationship

The environment experienced by females can have long-lasting effects on offspring phenotype. The objective of this study was to determine if maternal stress-induced behaviour reprogramming in offspring is found in brook char and to test whether cortisol is the main mediator, by separating the potential effects of cortisol from that of other potential maternal factors. We exposed female brook trout (Salvelinus fontinalis) to different parallel treatments during the oogenesis period: undisturbed as controls (1) fed cortisol through food (2) or physically stressed by handling once a week (3). Additionally, we exposed half of the control eggs to a cortisol suspension before fertilisation (4). Cortisol consumption and handling did not elevate either maternal plasma or egg cortisol, although egg cortisol level was significantly increased when eggs were bathed in the suspension. We measured spatial learning and memory, boldness and neophobia in 6 month-old offspring and found no effects of treatments on learning, memory or behaviour. Our results suggest that the relationship between maternal stress, circulating and egg cortisol levels, other maternal factors, and behavioural reprogramming is context and species-specific.

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