Applications

2021 ◽  
pp. 153-172
Author(s):  
Jeffrey A. Hutchings
Keyword(s):  
Life History ◽  
Maximum Size ◽  
Individual Growth ◽  
Natural Mortality ◽  
Negative Consequences ◽  
Age At Maturity ◽  
Life History Variation ◽  
Vulnerability Assessments ◽  
Individual Growth Rate ◽  
Declining Species

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.

Individual Growth and Reproduction

2019 ◽  
pp. 38-56
Author(s):  
Ken H. Andersen
Keyword(s):  
Life History ◽  
Growth Model ◽  
Life Histories ◽  
Maximum Size ◽  
Individual Growth ◽  
Energy Budgets ◽  
Asymptotic Size ◽  
The Individual ◽  
Growth And Reproduction

This chapter develops descriptions of how individuals grow and reproduce. More specifically, the chapter seeks to determine the growth and reproduction rates from the consumption rate, by developing an energy budget of the individual as a function of size. To that end, the chapter addresses the question of how an individual makes use of the energy acquired from consumption. It sets up the energy budgets of individuals by formulating the growth model using so-called life-history invariants, which are parameters that do not vary systematically between species. While the formulation of the growth model in terms of life-history invariants is largely successful, there is in particular one parameter that is not invariant between life histories: the asymptotic size (maximum size) of individuals in the population. This parameter plays the role of a master trait that characterizes most of the variation between life histories.

scholarly journals Effects of temperature on individual growth rate and body size of a freshwater amphipod

1998 ◽  
Vol 76 (6) ◽  
pp. 1107-1116 ◽  
Author(s):  
Vadim E Panov ◽  
Donald J McQueen
Keyword(s):  
Growth Rates ◽  
Negative Relationship ◽  
Maximum Size ◽  
Growth Efficiency ◽  
Individual Growth ◽  
Summer Temperatures ◽  
Individual Growth Rate ◽  
Natural Temperature ◽  
Effects Of Temperature ◽  
The Relationship

Individual growth rates of the freshwater amphipod Hyalella azteca (Saussure) were measured in the littoral zone oftwo small oligotrophic Ontario lakes and in growth experiments over a natural temperature gradient (10, 15, 20, and 238C).Field observations showed that a temperature of 208C is important for both the induction and termination of reproductiveresting stages in H. azteca. Growth rates were more affected by temperature in small than in large individuals. Growthparameters are related to rearing temperature by linear regressions, which can be used as a simple model for bioenergeticscalculations in crustaceans. A negative relationship between water temperature and maximum size attained by the amphipodswas found. The largest adults were absent in studied populations when summer temperatures were high, and this phenomenon,which has also been observed in other aquatic invertebrates, was bioenergetically determined. Energy-budget estimationsshowed negative net growth efficiency (K2) in the largest adults at temperatures above 208C. The relationship between K2andtemperature showed a dome-shaped pattern, K2values for larger amphipods being maximal at lower temperatures. Seasonalmigrations of adult H. azteca from shallow littoral to deeper cold habitats, observed in lakes during the warmest periods, appearto be temperature-induced and bioenergetically advantageous, despite probable increases in predation risk experienced inspatially simple deep-water habitats.

scholarly journals Genetic correlation between sea age at maturity and iteroparity in Atlantic salmon

2018 ◽  
Author(s):  
Tutku Aykanat ◽  
Mikhail Ozerov ◽  
Juha-Pekka Vähä ◽  
Panu Orell ◽  
Eero Niemelä ◽  
...  
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Genetic Correlations ◽  
Age Groups ◽  
Life History Trait ◽  
Age At Maturity ◽  
Life History Variation ◽  
Functional Link ◽  
Physiological Basis ◽  
Genome Region

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.

scholarly journals Growth and biological characteristics of pike perch Sander lucioperca (Linnaeus, 1758) in the Amur River

2020 ◽  
Vol 200 (3) ◽  
pp. 571-585
Author(s):  
N. N. Semenchenko ◽  
E. V. Ostrovskaya
Keyword(s):  
River Estuary ◽  
Maximum Size ◽  
Individual Growth ◽  
Biological Parameters ◽  
Amur River ◽  
Weight Growth ◽  
Amur Estuary ◽  
Pike Perch ◽  
The Amur River ◽  
Individual Growth Rate

Linear and weight growth of pike perch in the Amur River estuary is considered using the data on age determined for 197 specimens. The growth is described by von Bertalanffy and Schmalhausen equations. Some biological parameters of pike perch as the maximum size, age of mass maturation, etc. are calculated using the age-differentiated coefficients of natural mortality. The growth and biological parameters of pike perch in the Amur estuary are compared with the same parameters of this species in the Amur River at Khabarovsk. Recently 3 ecological forms of pike perch are distinguished in the Amur basin: i) riverine ecotype self-redistributed from Lake Khanka, ii) lacustrine ecotype in the lower Amur River, and iii) highly productive semi-anadromous marime ecotype in the Amur estuary. The 3rd phase of pike perch acclimatization is observed now in the Amur estuary known as the «bloom» phase accompanied with prominent increasing of population abundance and individual growth rate acceleration. Pike perch prey in this area mainly on juveniles of non-anadromous and diadromous fish, or on pond smelt Hypomesus olidus during their concentration in the estuary in winter.

scholarly journals Genetic coupling of life-history and aerobic performance in juvenile Atlantic salmon

2021 ◽  
Author(s):  
Jenni M. Prokkola ◽  
Eirik R Åsheim ◽  
Sergey Morozov ◽  
Paul Bangura ◽  
Jaakko Erkinaro ◽  
...  
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Metabolic Rate ◽  
Aerobic Performance ◽  
Age At Maturity ◽  
Life History Variation ◽  
Early Maturation ◽  
Genomic Regions ◽  
Late Maturation

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.

scholarly journals Alternative Migratory Strategies Related to Life History Differences in the Walleye (Sander Vitreus)

2021 ◽  
Author(s):  
Graydon McKee ◽  
Rachael Hornsby ◽  
Friedrich Fischer ◽  
Erin S. Dunlop ◽  
Robert Mackereth ◽  
...  
Keyword(s):  
Life History ◽  
Acoustic Telemetry ◽  
Late Summer ◽  
Maximum Size ◽  
Individual Growth ◽  
Sander Vitreus ◽  
Differential Growth ◽  
Individual Behaviour ◽  
Pace Of Life ◽  
Average Maximum

Abstract BackgroundWhile Pace of Life Syndrome predicts behavioural differences between individuals with differential growth and survival, testing these predictions in nature is challenging due to difficulties with measuring individual behaviour in the field. However, recent advances in acoustic telemetry technology have facilitated measurements of individual behaviour at scales not previously possible in aquatic ecosystems. MethodsUsing a Walleye (Sander vitreus) population inhabiting Black Bay, Lake Superior, we examine whether life history characteristics differ between more and less mobile individuals as predicted by Pace of Life Syndrome. We tracked the movement of 192 individuals from 2016-2019 using an acoustic telemetry study, relating patterns in annual migratory behaviour to individual growth, and seasonal changes in optimal thermal-optical habitat. ResultsWe observed two consistent movement patterns in our study population — migratory individuals left Black Bay during late summer to early fall before returning to the bay, whereas residents remained within the bay year-round. The average maximum length of migrant Walleye was 5.5 cm longer than residents, and the sex ratios of Walleye caught during fall surveys was increasingly female-biased towards the mouth of Black Bay, suggesting that a majority of migrants were females. Further, Walleye occupancy outside of Black Bay was positively associated with increasing thermal-optical habitat. ConclusionsWalleye in Black Bay appear to conform to Pace of Life Syndrome, with more exploratory (migrant) individuals gaining increased fitness through increased maximum size, which, given size-dependent fecundity in this species, likely results in greater reproductive success (via greater egg deposition vs. non-migrants). Further, apparent environmental (thermal) controls on migration suggest that migratory Walleye (more so than residents) may be more sensitive to changing environmental conditions (e.g., warming climate) than residents.

The effects of social status on life-history variation in juvenile salmon

1990 ◽  
Vol 68 (12) ◽  
pp. 2630-2636 ◽  
Author(s):  
Neil B. Metcalfe ◽  
Felicity A. Huntingford ◽  
John E. Thorpe ◽  
Colin E. Adams
Keyword(s):  
Life History ◽  
Social Status ◽  
Growth Rates ◽  
Individual Growth ◽  
Laboratory Population ◽  
High Status ◽  
Life History Variation ◽  
High Ranking ◽  
Clear Cut ◽  
Modal Group

Under good growing conditions, juvenile Atlantic salmon metamorphose into the migratory smolt stage at 1+ or 2+ years of age. The life-history decision on whether or not to migrate at 1+ years is made in July–August of the previous year. After this time, populations develop a bimodal size distribution, the larger fish (upper modal group) being the 1+ smolts and the lower modal group being fish that will smolt at 2+. Fish of high social status are more likely to become 1+ smolts. We examined the causal nature of this relationship by manipulating status within a laboratory population of sibling fish. The absolute status of individual fish was estimated within 2 weeks of first feeding. Relative status was then manipulated by dividing the population into two, half containing the fish with the highest absolute status (high ranking) and the remaining half of fish of lowest absolute status (low ranking). The status of individually marked fish was then determined within each of the two groups. Individual growth rates were monitored until smolting strategies were apparent. There was a complete overlap in the sizes of subsequent upper and lower modal group parr in early June, but from late June onwards fish in the upper modal group grew faster. The high- and low-ranking groups did not differ either in mean growth rates or in the proportions of fish adopting the alternative smolting strategies. However, they differed in the factors that influenced an individual's developmental strategy: within the high-ranking group, relative social status in June was a significant predictor of whether a fish would smolt aged 1+, whereas length at that time was not. In contrast, no relationship between status and smolting strategy was found in the low-ranking group, where differences in status were less clear-cut and had less influence on growth. Instead, age of smolting could be predicted from early growth rate. These results demonstrate that the influence of status on smolting depends on the extent to which fish of high status suppress the growth of those lower in the hierarchy.

Life-history variation among populations of Canadian Toads in Alberta, Canada

2005 ◽  
Vol 83 (11) ◽  
pp. 1421-1430 ◽  
Author(s):  
Brian R Eaton ◽  
Cynthia A Paszkowski ◽  
Kent Kristensen ◽  
Michelle Hiltz
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Life History Traits ◽  
Age At Maturity ◽  
Life History Variation ◽  
Size At Age ◽  
Almost All ◽  
Conservation Plans ◽  
Toad Bufo ◽  
Latitudinal Range

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.

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
Keyword(s):  
Life History ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Climatic Conditions ◽  
Age At Maturity ◽  
Life History Variation ◽  
High Productivity ◽  
Variation Range ◽  
Procrustean Analysis ◽  
Impacts Of Climate Change

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.

scholarly journals Demographic Traits Variation in a Pyrenean Newt (Calotriton asper) among Lacustrine and Stream Populations

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 471
Author(s):  
Sebastià Camarasa ◽  
Neus Oromi ◽  
Delfí Sanuy ◽  
Fèlix Amat
Keyword(s):  
Life History ◽  
Body Size ◽  
Age Structure ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Size Structure ◽  
Maximum Size ◽  
Sexually Dimorphic ◽  
Age At Maturity ◽  
Demographic Traits

Demographic traits were analyzed in the Pyrenean brook newt (Calotriton asper) to evaluate whether its variability responds to the adaptation to the different habitats. In this study, life history traits of Calotriton asper were studied in nine populations living in two different kinds of habitats in the Pyrenees mountains: lakes and streams. Skeletochronology was used to determine age structure and different traits such as age at maturity and longevity. Age structure was different between populations and sexes. The two lacustrine populations, with facultative pedomorphosis, attained their maturity earlier. Age at sexual maturity ranged from 4 to 9 years and in some populations was similar between sexes while in others, females matured at younger ages than males. Maximum longevity varied from 7 to 35 years among populations and was correlated with the age at sexual maturity. Body size differed among populations, was sexually dimorphic, and this disparity was not related to the kind of habitat. The maximum size was found in the lacustrine population but exhibited high variation between populations. The results obtained show a significant variability between sexes and populations, in age and body size structure of Calotriton asper that did not depend on the habitat.

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