Variations in juvenile growth, energy allocation and life-history strategies of two populations of Arctic charr in North Norway

2000 ◽  
Vol 56 (2) ◽  
pp. 328-346 ◽  
Author(s):  
A. H. Rikardsen ◽  
J. M. Elliott
Keyword(s):  
Life History ◽  
Arctic Charr ◽  
Energy Allocation ◽  
Life History Strategies ◽  
Juvenile Growth ◽  
Growth Energy ◽  
Two Populations ◽  
North Norway

scholarly journals State-dependent energy allocation in cod (Gadus morhua)

2006 ◽  
Vol 63 (1) ◽  
pp. 186-199 ◽  
Author(s):  
Christian Jørgensen ◽  
Øyvind Fiksen
Keyword(s):  
Life History ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Energy Allocation ◽  
Marine Ecology ◽  
Life History Strategies ◽  
Special Importance ◽  
State Dependent ◽  
Growth Energy ◽  
State Of The Environment

Growth and maturation are processes that are tuned to the external environment that an individual is likely to experience, where food availability, the mortality regime, and events necessary to complete the life cycle are of special importance. Understanding what influences life history strategies and how changes in life history in turn influence population dynamics and ecological interactions are crucial to our understanding of marine ecology and contemporary anthropogenic induced change. We present a state-dependent model that optimises life-long energy allocation in iteroparous fish. Energy can be allocated to growth or reproduction and depends in the individual's age, body length, and stored energy and the state of the environment. Allocation and the physiological processes of growth, energy storage, and reproduction are modelled mechanistically. The model is parameterised for Atlantic cod (Gadus morhua), more specifically the Northeast Arctic cod stock. Growth and maturation predicted by the model fit well with field observations, and based on a further investigation of cod reproduction in the model, we conclude that the model has the ability to recapture complex life history phenomena, e.g., indeterminate growth and skipped spawning, and therefore provides an important tool that can improve our understanding of life history strategies in fish.

Demography of Xenosaurus platyceps (Squamata: Xenosauridae): a comparison between tropical and temperate populations

2008 ◽  
Vol 29 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Carissa Jones ◽  
Isaac Rojas-González ◽  
Julio Lemos-Espinal ◽  
Jaime Zúñiga-Vega
Keyword(s):  
Life History ◽  
Population Growth ◽  
Adult Mortality ◽  
Life History Strategies ◽  
Relative Importance ◽  
Theoretical Frameworks ◽  
Population Growth Rates ◽  
Relative Contribution ◽  
Two Populations ◽  
Average Fitness

Abstract There appears to be variation in life-history strategies even between populations of the same species. For ectothermic organisms such as lizards, it has been predicted that demographic and life-history traits should differ consistently between temperate and tropical populations. This study compares the demographic strategies of a temperate and a tropical population of the lizard Xenosaurus platyceps. Population growth rates in both types of environments indicated populations in numerical equilibrium. Of the two populations, we found that the temperate population experiences lower adult mortality. The relative importance (estimated as the relative contribution to population growth rate) of permanence and of the adult/reproductive size classes is higher in the temperate population. In contrast, the relative importance for average fitness of fecundity and growth is higher in the tropical population. These results are consistent with the theoretical frameworks about life-historical differences among tropical and temperate lizard populations.

scholarly journals Environmentally Modulated Repeat Evolution of Polymorphic Arctic Charr Life History Traits

2021 ◽  
Vol 9 ◽  
Author(s):  
Gabrielle Grenier ◽  
Aslak Smalås ◽  
Runar Kjær ◽  
Rune Knudsen
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Growth Parameters ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Local Environment ◽  
Life History Strategies ◽  
Age At Maturity ◽  
First Time ◽  
Sympatric Morphs

Sympatric Arctic charr, Salvelinus alpinus (L. 1758), morphs have flexible but repeated life history strategies tested across five Norwegian lakes. In several Scandinavian polymorphic Arctic charr populations differentiated by their diet and habitat use, a large littoral omnivorous (LO) morph commonly cooccurs with a smaller profundal spawning (PB/PZ) morph. A third, large piscivorous (PP) morph is also known to occur within a portion of Arctic charr populations in the profundal habitat along with the PB/PZ individuals. Life history traits, such as age at maturity, growth, and diet are known to differ among coexisting morphs. Notably, the PP morph was the longest morph with the oldest age at maturity while the PB/PZ morph showed the shortest lengths overall and youngest age with LO morph being intermediate in both traits. Growth parameters differed across all the morphs. When examining growth within morph groups, the LO morph was found to have different growth across all lakes, while similar reproductive investments and different energy acquisition patterns were seen within the PB/PZ and PP morphs. These results suggest repeat evolution in several life history strategies of reproductively isolated Arctic charr sympatric morphs, notably for the first time in the PP morph, while also highlighting the importance of the local environment in modulating life history traits.

scholarly journals Low but significant genetic differentiation underlies biologically meaningful phenotypic divergence in a large Atlantic salmon population

2015 ◽  
Author(s):  
Tutku Aykanat ◽  
Susan E Johnston ◽  
Panu Orell ◽  
Eero Niemelä ◽  
Jaakko Erkinaro ◽  
...  
Keyword(s):  
Life History ◽  
Genetic Differentiation ◽  
Atlantic Salmon ◽  
Genetic Divergence ◽  
Natural Populations ◽  
Structured Populations ◽  
Life History Strategies ◽  
Adaptive Divergence ◽  
Juvenile Growth ◽  
Significant Genetic Differentiation

Despite decades of research assessing the genetic structure of natural populations, the biological meaning of low yet significant genetic divergence often remains unclear due to a lack of associated phenotypic and ecological information. At the same time, structured populations with low genetic divergence and overlapping boundaries can potentially provide excellent models to study adaptation and reproductive isolation in cases where high resolution genetic markers and relevant phenotypic and life history information are available. Here, we combined SNP-based population inference with extensive phenotypic and life history data to identify potential biological mechanisms driving fine scale sub-population differentiation in Atlantic salmon (Salmo salar) from the Teno River, a major salmon river in Europe. Two sympatrically occurring sub-populations had low but significant genetic differentiation (FST = 0.018) and displayed marked differences in the distribution of life history strategies, including variation in juvenile growth rate, age at maturity and size within age classes. Large, late-maturing individuals were virtually absent from one of the two sub-populations and there were significant differences in juvenile growth rates and size-at-age after oceanic migration between individuals in the respective sub-populations. Our findings suggest that different evolutionary processes affect each sub-population and that hybridization and subsequent selection may maintain low genetic differentiation without hindering adaptive divergence.

scholarly journals Differential reproductive responses to stress reveal the role of life-history strategies within a species

2013 ◽  
Vol 280 (1771) ◽  
pp. 20132090 ◽  
Author(s):  
J. Schultner ◽  
A. S. Kitaysky ◽  
G. W. Gabrielsen ◽  
S. A. Hatch ◽  
C. Bech
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Life History Strategies ◽  
Short Term ◽  
Food Shortages ◽  
Investment In Reproduction ◽  
Response To Stress ◽  
Environmental Events ◽  
Two Populations

Life-history strategies describe that ‘slow’- in contrast to ‘fast’-living species allocate resources cautiously towards reproduction to enhance survival. Recent evidence suggests that variation in strategies exists not only among species but also among populations of the same species. Here, we examined the effect of experimentally induced stress on resource allocation of breeding seabirds in two populations with contrasting life-history strategies: slow-living Pacific and fast-living Atlantic black-legged kittiwakes. We tested the hypothesis that reproductive responses in kittiwakes under stress reflect their life-history strategies. We predicted that in response to stress, Pacific kittiwakes reduce investment in reproduction compared with Atlantic kittiwakes. We exposed chick-rearing kittiwakes to a short-term (3-day) period of increased exogenous corticosterone (CORT), a hormone that is released during food shortages. We examined changes in baseline CORT levels, parental care and effects on offspring. We found that kittiwakes from the two populations invested differently in offspring when facing stress. In response to elevated CORT, Pacific kittiwakes reduced nest attendance and deserted offspring more readily than Atlantic kittiwakes. We observed lower chick growth, a higher stress response in offspring and lower reproductive success in response to CORT implantation in Pacific kittiwakes, whereas the opposite occurred in the Atlantic. Our findings support the hypothesis that life-history strategies predict short-term responses of individuals to stress within a species. We conclude that behaviour and physiology under stress are consistent with trade-off priorities as predicted by life-history theory. We encourage future studies to consider the pivotal role of life-history strategies when interpreting inter-population differences of animal responses to stressful environmental events.

scholarly journals Lifelong divergence of growth patterns in Arctic charr life history strategies: implications for sustainable fisheries in a changing climate

2021 ◽  
Author(s):  
Gabrielle Grenier ◽  
Ross F. Tallman
Keyword(s):  
Life History ◽  
Life Histories ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Growth Increment ◽  
Linear Increase ◽  
Growth Patterns ◽  
Life History Strategies ◽  
Changing Climate ◽  
Summer Growth

Arctic charr (Salvelinus alpinus Linneaus, 1758) are phenotypically variable with multiple life history strategies including anadromous and freshwater resident individuals. The mechanism determining life history is believed to be set early in life. Anadromous individuals show greater seasonality in growth and feeding after the first seaward migration relative to resident conspecifics. We used otolith growth increment measurements to estimate lifelong growth patterns for 355 individuals with anadromous or resident life history from four populations within Cumberland Sound, Nunavut. Using a general and a generalized linear model, we discovered a linear increase (estimate = 0.006) in growth for both Arctic charr life histories between 1990 and 2016. Resident Arctic charr have lower annual growth (estimate = -0.176) and show a decrease in the annual proportion of summer growth as they age (estimate = -0.042) while their anadromous counterparts maintain a higher seasonality in their growth patterns with age. This suggests that growth is indeed important in life history trajectory for Arctic charr and that seasonal growth patterns differ among life histories. The results highlight the importance of improving our understanding of mechanisms influencing life history trajectory in Arctic charr to ensure sustainability of harvested Arctic charr populations in a changing climate.

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