Life history differences parallel environmental differences among North American lake trout (Salvelinus namaycush) populations

2010 ◽  
Vol 67 (2) ◽  
pp. 314-325 ◽  
Author(s):  
Jenni L. McDermid ◽  
Brian J. Shuter ◽  
Nigel P. Lester

Lake trout ( Salvelinus namaycush ) exhibit substantial life history variation range-wide and at a local scale. This study addresses two hypotheses that have been proposed to account for this: (i) over the zoogeographic range, climatic conditions are associated with life history differences; and (ii) within smaller geographic regions, physical lake attributes are associated with life history differences. Multivariate statistics (Procrustean analysis and canonical correlation analysis) identified a strong, range-wide association between climate and life history variables. Colder climates were associated with slower prematuration growth, older age at maturity, and increased longevity. Winter conditions were also important; longer, warmer winters were associated with slower prematuration growth, smaller maximum sizes, and increased weight at a standard length of 425 mm. In southern populations, these general trends were further modified by physical lake attributes. High productivity lakes had lake trout with faster prematuration growth and larger maximum sizes; deeper lakes were associated with larger maximum sizes and later ages at maturity; and larger lakes were associated with slower prematuration growth, greater longevity, and larger maximum sizes. This study identifies abiotic variables that should be incorporated into existing lake trout management models, thus extending their applicability range-wide and permitting them to deal with possible impacts of climate change.

2018 ◽  
Vol 75 (7) ◽  
pp. 1070-1081 ◽  
Author(s):  
Benjamin C. Kissinger ◽  
Les N. Harris ◽  
Danny Swainson ◽  
W. Gary Anderson ◽  
Margaret F. Docker ◽  
...  

Partial anadromy is common within salmonid populations, where resident and anadromous individuals interbreed and overlap in habitat use during portions of life. Deviation to this definition occurs within the Husky Lakes drainage basin (HLDB), Northwest Territories, where freshwater resident, semi-anadromous, and brackish-water resident lake trout (Salvelinus namaycush) life history types are documented. In this study, microsatellite DNA variation was assayed to evaluate genetic structuring among life history types from the HLDB and adjacent lower Mackenzie River system. Significant differentiation was resolved among most locations and life histories (global FST = 0.192). Brackish-water residents were differentiated from all locations and life histories, including sympatric semi-anadromous individuals, providing evidence for genetically fixed strategies. Also, this provides the first evidence of breeding partial migration in salmonids using brackish-water environments, where brackish-water residents and semi-anadromous migrants interact during the nonbreeding season, but the latter migrate elsewhere to spawn. Alternatively, the lack of genetic differentiation between semi-anadromous and Sitidgi Lake residents suggests conditional mating tactics may also influence partial anadromy. This work provides novel insights into partial anadromy in Arctic salmonids and expands our knowledge of biodiversity in this region.


2008 ◽  
Vol 29 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Carlo Utzeri ◽  
Claudio Angelini ◽  
Damiano Antonelli

Abstract We studied nine populations of Salamandrina perspicillata for two to nine years and described the life history variation among these population. Despite experiencing similar climatic conditions, populations differed in mean body size: populations using still water bodies for oviposition were larger body-sized than those using brooks. One semi-natural pond was used by particularly small individuals and was probably recently colonised. The mean body size of ovipositing females varied from year to year. Measurements of individuals in successive years showed that the tail grew more than the trunk and this differential growth increased with age. Females did not oviposit every year and, within a given population, the number of ovipositing females varied widely from year to year.


2018 ◽  
Author(s):  
Tutku Aykanat ◽  
Mikhail Ozerov ◽  
Juha-Pekka Vähä ◽  
Panu Orell ◽  
Eero Niemelä ◽  
...  

AbstractGenetic correlations in life history traits may result in unpredictable evolutionary trajectories if not accounted for in life-history models. Iteroparity (the reproductive strategy of reproducing more than once) in Atlantic salmon (Salmo salar) is a fitness trait with substantial variation within and among populations. In the Teno River in northern Europe, iteroparous individuals constitute an important component of many populations and have experienced a sharp increase in abundance in the last 20 years, partly overlapping with a general decrease in age structure. The physiological basis of iteroparity bears similarities to that of age at first maturity, another life history trait with substantial fitness effects in salmon. Sea age at maturity in Atlantic salmon is controlled by a major locus around the vgll3 gene, and we used this opportunity demonstrate that the two traits are genetically correlated around this genome region. The odds ratio of survival until second reproduction was up to 2.4 (1.8-3.5 90% CI) times higher for fish with the early-maturing vgll3 genotype (EE) compared to fish with the late-maturing genotype (LL). The association had a dominance architecture, although the dominant allele was reversed in the late-maturing group compared to younger groups that stayed only one year at sea before maturation. Post hoc analysis indicated that iteroparous fish with the EE genotype had accelerated growth prior to first reproduction compared to first-time spawners, across all age groups, while this effect was not detected in fish with the LL genotype. These results broaden the functional link around the vgll3 genome region and help us understand constraints in the evolution of life history variation in salmon. Our results further highlight the need to account for genetic correlations between fitness traits when predicting demographic changes in changing environments.


2021 ◽  
Author(s):  
Jenni M. Prokkola ◽  
Eirik R Åsheim ◽  
Sergey Morozov ◽  
Paul Bangura ◽  
Jaakko Erkinaro ◽  
...  

1. The physiological underpinnings of life history adaptations in ectotherms are not well understood. Theories suggest energy metabolism influences life history variation via modulation of resource acquisition. However, the genetic basis of this relation and its dependence on ecological conditions, such as food availability, have rarely been characterized, despite being critical to predicting the responses of populations to environmental changes. 2. The Atlantic salmon (Salmo salar) is an emerging wild model species for addressing these questions; strong genetic determination of age-at-maturity at two unlinked genomic regions (vgll3 and six6) enables the use of complex experimental designs and tests of hypotheses on the physiological and genetic basis of life-history trait variation. 3. In this study, we crossed salmon to obtain individuals with all combinations of late and early maturation genotypes for vgll3 and six6 within full-sib families. Using more than 250 juveniles in common garden conditions, we tested (i) whether metabolic phenotypes (i.e., standard and maximum metabolic rates, and absolute aerobic scope) were correlated with the age-at-maturity genotypes and (ii) if high vs. low food availability modulated the relationship. 4. We found that salmon with vgll3 early maturation genotype had a higher aerobic scope and maximum metabolic rate, but not standard metabolic rate, compared to salmon with vgll3 late maturation genotype. This suggests that physiological or structural pathways regulating maximum oxygen supply or demand are potentially important for the determination of age-at-maturity in Atlantic salmon. 5. Vgll3 and six6 exhibited physiological epistasis, whereby maximum metabolic rate significantly decreased when late maturation genotypes were present concurrently in both loci compared to other genotype combinations. 6. The growth of the feed restricted group decreased substantially compared to the high food group. However, the effects of life-history genomic regions were similar in both feeding regimes, indicating a lack of genotype-by-environment interactions. 7. Our results indicate that aerobic performance of juvenile salmon may affect their age-at-maturity. The results may help to better understand the mechanistic basis of life-history variation, and the metabolic constrains on life-history evolution.


2016 ◽  
Vol 42 (2) ◽  
pp. 193-203 ◽  
Author(s):  
Louise Chavarie ◽  
Kimberly Howland ◽  
Paul Venturelli ◽  
Benjamin C. Kissinger ◽  
Ross Tallman ◽  
...  

2014 ◽  
Vol 71 (1) ◽  
pp. 10-20 ◽  
Author(s):  
Craig P. Stafford ◽  
Megan V. McPhee ◽  
Lisa A. Eby ◽  
Fred W. Allendorf

We found that an introduced population of lake trout (Salvelinus namaycush) in Flathead Lake, Montana, USA, exhibited divergent life history, diet, and morphology after the invasion of Mysis diluviana. A correspondence between stable isotopes (δ13C and δ15N) in lake trout muscle and their prey suggests that individual lake trout exhibited depth preferences. Lake trout 451–600 mm total length showed morphological distinctness between shallow (0–25 m) and deep (60–100 m) collections wherein the latter had deeper bodies and larger eyes. Furthermore, these deep lake trout fed more heavily on Mysis, grew slower, and matured at a smaller size. Lack of genetic divergence between depth groups and the rapid divergence of life histories after Mysis invasion suggest a strong role for environment in producing the observed ecotypic variation. Our research supports resource partitioning by depth and diet as a drivers of phenotypic diversity in lake trout, providing insights into the origins of morphotypes and guidance for conservation of native populations.


2005 ◽  
Vol 83 (11) ◽  
pp. 1421-1430 ◽  
Author(s):  
Brian R Eaton ◽  
Cynthia A Paszkowski ◽  
Kent Kristensen ◽  
Michelle Hiltz

Development of appropriate conservation plans relies on life-history information and how life-history traits vary across populations of a species. Such data are lacking for many amphibians, including the Canadian Toad (Bufo hemiophrys Cope, 1886). Here we use skeletochronology to estimate size at age, growth rates, age at maturity, and longevity of toads from nine populations along a latitudinal gradient in Alberta, Canada. Size of individual toads within each year class was highly variable, but age and size (measured as snout-to-urostyle length) were significantly related for almost all populations. The largest individuals were found in the southern-most population, while the smallest toads were found in three populations from the middle of the latitudinal range studied. Growth rates were highest in the southern-most population and lowest at the three populations with relatively small individuals. Maximum age was from 7 to 12 years for the populations sampled. The oldest individuals were found in populations in the middle of the latitudinal range sampled; toads in these populations were smaller than those in all other populations. Age at maturity was 1 year old for males and 2 years old for females in most populations. This study shows that some life-history traits exhibit significant variation between Canadian Toad populations, suggesting that effective conservation of this species will need to include population or area-specific management.


2021 ◽  
pp. 153-172
Author(s):  
Jeffrey A. Hutchings

By affecting age-specific survival and fecundity, human-induced disturbances affect life history. This has potential to affect r max with negative consequences for species viability and persistence. Several types of assessments are used to classify vulnerability to extinction, exploitation, and climate change. When information on r max is unavailable, vulnerability assessments often rely on life-history correlates of r max. These have included generation time, age at maturity, maximum size, longevity, fecundity, natural mortality, and individual growth rate. Empirical research indicates that links with r max are strong for some traits, such as age at maturity and body size, but weak for others, such as fecundity. In addition to assessments of declining species, efforts have been made to identify life-history correlates of the rate and uncertainty in species recovery. Persistence and stability can be strengthened by the magnitude of life-history variation. The greater the variability in life history within and among, the greater the resistance and resilience of populations and species.


2007 ◽  
Vol 71 (1) ◽  
pp. 1-16 ◽  
Author(s):  
J. D. Fitzsimons ◽  
J. L. Jonas ◽  
R. M. Claramunt ◽  
B. Williston ◽  
G. Williston ◽  
...  

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