Life History Tactics Research Articles

Phenotypic plasticity of habitat use by three temperate eel species, Anguilla anguilla, A. japonica and A. rostrata

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 308:231-241 (2006) - doi:10.3354/meps308231 Phenotypic plasticity of habitat use by three temperate eel species, Anguilla anguilla, A. japonica and A. rostrata Françoise Daverat1,*, Karin E. Limburg2, Isabel Thibault3, Jen-Chieh Shiao4, Julian J. Dodson3, François Caron6, Wann-Nian Tzeng7, Yoshiyuki Iizuka5, Håkan Wickström8 1Cemagref, 50 Avenue de Verdun, 33612 Cestas, France 2SUNY College of Environmental Science & Forestry, Syracuse, New York 13210, USA 3Département de Biologie, Université Laval, Ste-Foy, Québec G1K 7P4, Canada 4Institute of Cellular and Organismic Biology, and 5Institute of Earth Sciences, Academia Sinica, 128, Section 2, Academia Road, Nankang, Taipei, Taiwan 115, ROC 6Ministère des Ressources Naturelles et de la Faune du Québec, 675, boul. René-Lévesque Est, Québec (Québec) G1R 5V7, Canada 7Institute of Fisheries Science, College of Life Science, National Taiwan University, Taipei, Taiwan 106, ROC 8Swedish Board of Fisheries, Institute of Freshwater Research, SE-178 93, Drottningholm, Sweden *Email: francoise.daverat@cemagref.fr ABSTRACT: Habitat use patterns of 3 species of temperate eels, Anguilla anguilla, A. japonica and A. rostrata, were investigated using otolith strontium:calcium ratio life history transects. Published and unpublished data from 6 sites (Canada, United States, Sweden, France, Taiwan and Japan) sampled across the geographical range of each eel species were compiled. Sr:Ca patterns indicated that the 3 species displayed similar patterns of habitat use. In all sites, patterns of habitat use consisted of either residency in one habitat (fresh, brackish, or marine) or movements between habitats. One movement pattern consisted of either a single change or 2 changes of habitat from fresh to brackish waters, or from brackish water to freshwater. Seasonal movements between fresh and brackish waters were observed for all 3 species. When only a single habitat switch event was detected, it occurred between 3 and 5 yr of age. Occurrence of eels with no freshwater experience was demonstrated, but such eels accounted for a smaller proportion of the overall sample than eels with some (even brief) freshwater experience. Contrary to the common convention that these are obligate catadromous species, we must now consider them as facultative catadromous, with far more flexibility in habitat use. The most variable parameter among study sites was the relative proportion, rather than the diversity, of lifetime spent in the various habitat use patterns. Eels found at higher latitudes exhibited a greater probability of remaining in the lower reaches of watersheds in brackish water. Diversity of habitat use appears to be a common strategy of temperate eel species, and, as a life history tactic, is under environmental control. KEY WORDS: Habitat use · Anguilla spp · Otolith Sr:Ca Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 308. Online publication date: February 16, 2006 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2006 Inter-Research.

HIGH SURVIVAL IN POOR YEARS: LIFE HISTORY TACTICS ADAPTED TO MAST SEEDING IN THE EDIBLE DORMOUSE

Edible dormice (Glis glis) reproduce in years with beech mast seeding, but entire populations may skip reproduction in years when tree seeds, a major food resource of this small hibernator, are absent. We tested the hypothesis that the year-to-year variability in reproductive effort caused by this breeding strategy should lead to detectable differences in yearly survival rates. Therefore, we analyzed capture-recapture data from animals occupying nest boxes, collected over nine years at two study sites in Germany. Among fully grown adults (aged two years or older), survival probabilities were significantly lower (0.32 +/- 0.04) after reproductive years (n = 5) compared to years (n = 4) with absent or below-average reproduction (0.58 +/- 0.07) on both study sites. This trade-off between reproduction and subsequent survival was observed in both females and males and appears to be a relatively rare case in which costs of reproduction in terms of longevity are detectable at the population level. Effects of reproduction on survival were less pronounced when yearlings (with a generally lower reproductive effort) were included and were more distinct in a suboptimal habitat. Of those females breeding in nest boxes, 96.5% had only one or two litters within the study period. Considering these and previously published results, including a report of extremely high mean longevities (9-12 years) of dormice in a habitat with infrequent mast seeding, we conclude that edible dormice flexibly adjust life history tactics to local mast patterns. Long stretches of mast failures can in fact lead to relative semelparity, i.e., a strategy in which dormice "sit tight" for several years until environmental conditions are favorable for reproduction.

Muscle biochemistry and the ontogeny of flight capacity during behavioral development in the honey bee,Apis mellifera

A fundamental issue in physiology and behavior is underlie major behavioral shifts in organisms as they transitions are common in nature and include the age-related switch from nest/hive work to foraging in social insects such as honey bees (understanding the functional and genetic mechanisms that adopt new environments or life history tactics. Such). Because of their experimental Apis mellifera tractability, recently sequenced genome and well understood biology, honey bees are an ideal model system for integrating molecular, genetic, physiological and sociobiological perspectives to advance understanding of behavioral and life history transitions. When honey bees (Apis mellifera) transition from hive work to foraging, their flight muscles undergo changes Apis mellifera that allow these insects to attain the highest rates of flight muscle metabolism and power output ever recorded in the animal kingdom. Here, we review research to date showing that honey bee flight muscles undergo significant changes in biochemistry and gene expression and that these changes accompany a significant increase in the capacity to generate metabolic and aerodynamic power during flight. It is likely that changes in muscle gene expression, biochemistry, metabolism and functional capacity may be driven primarily by behavior as opposed to age, as is the case for changes in honey bee brains.

A continuum of life history tactics in a brown trout (Salmo trutta) population

Life history tactics of the brown trout (Salmo trutta) population of the Oir River (Normandy, France) were studied using passive integrated transponder (PIT) tagging data of five consecutive cohorts (5900 individuals) monitored between 1995 and 2002. Results demonstrate that (i) life history traits vary among cohorts, chiefly caused by environmental variability, (ii) juvenile growth, particularly second-year growth, plays an important role in the determination of the growing environment and trout exhibit variable migratory behaviour (from remaining in the natal brook to migrating in the sea) related to their juvenile growth rate, and (iii) the description of life history tactics (including juvenile growth, fine-scale migratory behaviour, and reproduction) can be clarified. Tactics are expressed along a continuum in time (age to reproduce) and space (distance of migration). Flexible life history tactics varying with juvenile growth is consistent with previous studies, but the use of empiric data on growth and migration from PIT tagging allows refining the description of life history tactics, taking into account their continuous distribution in time and space.

Generation Time: A Reliable Metric to Measure Life‐History Variation among Mammalian Populations

Oli and Dobson proposed that the ratio between the magnitude and the onset of reproduction (F/ alpha ratio) allows one to predict the relative importance of vital rates on population growth rate in mammalian populations and provides a reliable measure of the ranking of mammalian species on the slow-fast continuum of life-history tactics. We show that the choice of the ratio F/ alpha is arbitrary and is not grounded in demographic theory. We estimate the position on the slow-fast continuum using the first axis of a principal components analysis of all life-history variables studied by Oli and Dobson and show that most individual vital rates perform as well as the F/ alpha ratio. Finally, we find, in agreement with previous studies, that the age of first reproduction is a reliable predictor of the ranking of mammalian populations along the slow-fast continuum and that both body mass and phylogeny markedly influence the generation time of mammalian species. We conclude that arbitrary ratios such as F/ alpha correlate with life-history types in mammals simply because life-history variables are highly correlated in response to allometric, phylogenetic, and environmental influences. We suggest that generation time is a reliable metric to measure life-history variation among mammalian populations and should be preferred to any arbitrary combination between vital rates.

The Influence of Ecological Factors on the Distribution and the Genetic Structure of Escherichia coli.

This review focuses on recent data concerning the ecological factors that determine the distribution of Escherichia coli and the genetic structures of naturally occurring E. coli populations. It summarizes some of the older literature concerning the dynamics of E. coli populations within a host and poses some questions that arise from our more recently acquired understanding of the factors affecting the genetic structures of E. coli populations. Multilocus enzyme electrophoresis (MLEE) studies indicate that E. coli, relative to other members of the family Enterobacteriaceae, exhibits a moderate degree of genetic diversity. The existence of subspecific structure in E. coli has for the most part been determined by largely neutral in its effects on the fitness of a strain. The consequences for E. coli of the transition between its primary and secondary habitats are of considerable practical significance for water quality assessment and disease transmission. E. coli causes a significant fraction of human bacterial disease and is responsible for two main types of disease in humans and domestic animals: diarrheal disease and extraintestinal infections. The observed distribution of strains from the different E. coli genetic groups indicates that they have different life history tactics and ecological niches. A and B1 strains appear to be generalists, as they can be recovered from any vertebrate group. Group B2 and D strains appear to be more specialized, as they are largely restricted to endothermic vertebrates.

Motility, ATP levels and metabolic enzyme activity of sperm from bluegill ( Lepomis macrochirus)

Male bluegill displays one of two life history tactics. Some males (termed “parentals”) delay reproduction until ca. 7 years of age, at which time they build nests and actively courts females. Others mature precociously (sneakers) and obtain fertilizations by cuckolding parental males. In the current study, we studied the relations among sperm motility, ATP levels, and metabolic enzyme activity in parental and sneaker bluegill. In both reproductive tactics, sperm swimming speed and ATP levels declined in parallel over the first 60 s of motility. Although sneaker sperm initially had higher ATP levels than parental sperm, by ∼30 s postactivation, no differences existed between tactics. No differences were noted between tactics in swimming speed, percent motility, or the activities of key metabolic enzymes, although sperm from parentals had a higher ratio of creatine phosphokinase (CPK) to citrate synthase (CS). In both tactics, with increasing CPK and CS activity, sperm ATP levels increased at 20 s postactivation, suggesting that capacities for phosphocreatine hydrolysis and aerobic metabolism may influence interindividual variation in rates of ATP depletion. Nonetheless, there was no relation between sperm ATP levels and either swimming speed or percent of sperm that were motile. This suggests that interindividual variation in ATP levels may not be the primary determinant of variation in sperm swimming performance in bluegill.

Long-term survival of adult Arctic grayling (Thymallus arcticus) in the Kuparuk River, Alaska

In many long-lived species such as Arctic grayling (Thymallus arcticus), population growth rate is most sensitive to changes in adult survival probabilities. Understanding the factors that regulate adult survival in this species should provide insight into the population dynamics of this and other long-lived Arctic species. Using the program MARK, we analyzed 17 years of mark–recapture data to estimate survival rates for Arctic grayling in the Kuparuk River, Alaska, from 1985 to 2000. Mean annual survival rates overall ranged from 0.39 to 1.0 and averaged 0.71 ± 0.05 for resident and 0.75 ± 0.05 for nonresident fish. Spending the summer in the more productive fertilized zone of the experimental reach had no influence on survival despite higher productivity on all trophic levels and consistently higher growth rates in Arctic grayling. None of the environmental (stream temperature, discharge, winter severity, and incidence of drought) or population parameters (growth, condition factor, and mean fish size) that we examined explained significant amounts of variance in survival rates. The lack of responsiveness of survival to annual environmental conditions was unexpected and suggests that multiyear factors or life history tactics that maintain survival at the expense of growth and fecundity likely determine survival.

Lasting effects of conditions at birth on moose body mass

Whether cohort effects can be retrieved in adult phenotypes depends on the possibility for individuals to compensate for a good or bad start in life. This ability to compensate may itself depend on the environment and on individual sex. In large polygynous ungulates, male reproductive success relies more on body size than the reproductive success of females, which makes them more sensitive to a bad start in life. Based on current theories of life history evolution and sexual selection, we tested the following predictions in a moose population: 1) cohort effects and year effects occur in both male and female adult body mass, but due to 2) compensatory growth, cohort effects tend to fade away with the individual's age; and 3) males are more sensitive to cohort effects than females. In support of the first prediction, we found that density and climate during the year‐of‐birth and the year‐of‐harvest affected moose body mass in both sexes. However, the magnitude of the effects of environmental conditions at birth on adult body mass decreased with increasing age, but less so in males than in females. Thus, as expected based on our third prediction, environmental conditions early in life were more influential on adult body mass of males compared to females. Such a result supports the existence of sex‐specific life history tactics, with males maximising growth rate and females rather trading‐off growth for reproduction.

Population dynamics and life history tactics of arthropods from Mediterranean‐type ecosystems

The null hypothesis of this paper is that survival of arthropods under the severe Mediterranean conditions involves specific combinations of conservative and conformist traits. To test this hypothesis a modeling approach employing a Leslie‐type matrix model and a fuzzy systems technique for parameter estimation is developed and applied to a model species. The general conclusion is that the results of this paper add support to the null hypothesis, whereas specific conclusions are as follows: 1) matrix models merging demographic and physiological parameters are suitable tools for the simulation of population dynamics of arthropods and further for the discussion of the interplay among life history traits; 2) employing linguistic instead of arithmetic variables, fuzzy approaches allow for the formalization of incomplete and/or missing data exploiting expertise concerning related species; 3) in general, population dynamics of arthropods follow the seasonality of the Mediterranean climate; 4) the basic mechanism underlying skewing phenologies and stochastic equilibrium is identified with the type of temperature dependence of arthropod metabolic activity; 5) under optimal conditions an exponential trend is superimposed on seasonal population dynamics; 6) more realistic conditions involving large‐scale random oscillation in temperature in autumn and spring coupled with small‐scale temperature oscillation in summer and winter result in stochastic equilibrium; 7) moderate contamination of soil and medium‐scale oscillation in temperature result in stable temporal patterns; 8) a sensitivity analysis shows disproportional effect of different demographic parameters on population growth rate. Fecundity of young and middle‐aged adults is most important for the rate of population growth, whereas elder animals are considered an important pool for maintenance of the population.

Fetal programming: Adaptive life-history tactics or making the best of a bad start?

Fetal programming is an ontogenetic phenomenon of increasing interest to human biologists. Because the downstream consequences of fetal programming have clear impacts on specific life-history traits (e.g., age at first reproduction and the general age-pattern of reproductive investments), a number of authors have raised the question of the adaptive significance of fetal programming. In this paper, I review in some detail several classical models in life-history theory and discuss their relative merits and weaknesses for human biology. I suggest that an adequate model of human life-history evolution must account for the highly structured nature of the human life cycle, with its late age at first reproduction, large degree of iteroparity, highly overlapping generations, and extensive, post-weaning parental investment. I further suggest that an understanding of stochastic demography is essential for answering the question of the adaptive significance of fetal programming, and specifically the finding of low birth weight on smaller adult body size and earlier age at first reproduction. Using a stage-structured stochastic population model, I show that the downstream consequences of early deprivation may be "making the best of a bad start" rather than an adaptation per se. When a high-investment strategy entails survival costs, the alternate strategy of early reproduction with relatively low investment may have higher fitness than trying to play the high-investment strategy and failing.

DIFFERENTIAL REPRODUCTIVE SUCCESS AND HERITABILITY OF ALTERNATIVE REPRODUCTIVE TACTICS IN WILD ATLANTIC SALMON (SALMO SALAR L)

A critical step in understanding the evolution and maintenance of alternative reproductive tactics is to obtain accurate comparisons of their fitness and to determine factors influencing individual status. In this study, we first used individual multilocus genotypic information to compare reproductive success between two alternative reproductive tactics of anadromous Atlantic salmon (Salmo salar L.) in their natural environments. We also documented the effects of the quality of the rearing environment and of paternal reproductive tactics on heritability of juvenile growth, which is an important component of individual status. Results showed that large dominant salmon (multisea winter) had higher reproductive success than smaller satellite individuals (grilse). Also, there was a status difference associated with both habitat and male tactic. Overall, offspring produced in streams were bigger than those produced in the main river stretch. Grilse also produced bigger offspring than those fathered by multisea winter males. Heritability of juvenile growth was significant but varied according to quality of habitat: higher heritability estimates were observed in higher quality habitats (streams) than in lower quality habitats (main river stretch). Heritability estimates for juvenile growth varied as well, depending on male tactic, with progeny fathered by multisea winter males having higher values than those fathered by grilse. Together, these results indicate that a combination of additive genetic effects, parental life history and habitat quality will ultimately shape juvenile growth rate, which is the main determinant of status and of subsequent choice of life-history tactics.

Western Sandpipers (Calidris Mauri) During the Nonbreeding Season: Spatial Segregation on a Hemispheric Scale

Abstract The nonbreeding distribution of Western Sandpipers (Calidris mauri) was documented using 19 data sets from 13 sites along the Pacific and Atlantic coasts of the Americas. Western Sandpipers showed latitudinal segregation with regard to sex and age. Females wintered farther south than males. A “U” shaped pattern was found with respect to age, with juveniles occurring at higher proportions at both the northern and southern ends of the range. Distribution of sexes might be affected by differences in bill length and a latitudinal trend in depth distribution of prey. For age class distribution, two different life-history tactics of juveniles might exist that are related to the higher cost of feather wear for juveniles compared to adults. Most juveniles complete three long-distance migrations on one set of flight feathers whereas adults complete two. Juveniles may winter either far north, thereby reducing feather wear induced by ultraviolet light, migration, or both, or far south and spend the summer on the nonbreeding area.

Life history strategies and habitat templets of tropical butterflies in north-eastern Australia

Three multivoltine species of satyrine butterflies in the genus Mycalesis (Lepidoptera: Nymphalidae) are narrowly sympatric in the wet–dry tropics of north-eastern Australia. They show a range of ecological strategies and adaptations associated with contrasting habitats and varying selective pressures. Two abiotic factors, namely favorability (the reciprocal of seasonal adversity) and predictability (broadly the reciprocal of disturbance), were examined as potential environmental selective forces in shaping their life histories. Comparison of several key life history traits of the lsquowet-season formrsquo revealed that the life histories of each species corresponded well with their habitat characteristics. M. perseus, which lives in habitats which are less favorable (i.e. adverse) and more unpredictable (i.e. temporary), shows many traits of an r-type strategy: smaller size, faster development, earlier maturation, higher fecundity, smaller egg size, and rapid population increase. By contrast, M. sirius and M. terminus, which live in more favorable and predictable (i.e. permanent) habitats, have many life history attributes and other characteristics in common which link them closer to K-type strategies. The only discrepancy is lower potential reproductive effort of M. perseus, which may be accounted for in terms of an evolutionary trade-off, such as with dispersal or dormancy. Other correlates associated with the M. perseus life history tactic include higher sex-size dimorphism, greater dispersal ability, better tolerance to adverse conditions, stronger phenotypic variation, greater degree of polyandry, and a more flexible breeding strategy. The life history patterns of these species are discussed in the context of evolutionary life history models, particularly the Southwood–Greenslade habitat templet.

WESTERN SANDPIPERS (CALIDRIS MAURI) DURING THE NONBREEDING SEASON: SPATIAL SEGREGATION ON A HEMISPHERIC SCALE

Abstract The nonbreeding distribution of Western Sandpipers (Calidris mauri) was documented using 19 data sets from 13 sites along the Pacific and Atlantic coasts of the Americas. Western Sandpipers showed latitudinal segregation with regard to sex and age. Females wintered farther south than males. A “U” shaped pattern was found with respect to age, with juveniles occurring at higher proportions at both the northern and southern ends of the range. Distribution of sexes might be affected by differences in bill length and a latitudinal trend in depth distribution of prey. For age class distribution, two different life-history tactics of juveniles might exist that are related to the higher cost of feather wear for juveniles compared to adults. Most juveniles complete three long-distance migrations on one set of flight feathers whereas adults complete two. Juveniles may winter either far north, thereby reducing feather wear induced by ultraviolet light, migration, or both, or far south and spend the summer o...

Effect of changing harem on timing of sex change in female cleaner fish Labroides dimidiatus

The cleaner wrasse Labroides dimidiatus has a haremic mating system. When the territorial dominant male disappears, the largest female of the harem changes sex and takes it over. During a 2.5-year field study on a high-density population, females sometimes temporarily intruded into neighbouring harems. Almost half of these females transferred to harems that they had frequently visited, suggesting that females may assess the social conditions of the harem during these visits. After the transfer, females increased in rank or escaped from similar-sized competitors in their former harem. As a result, such females could become the dominant male earlier than females that never changed harem. The females that transferred were reproductively active, but less fecund than females that did not. Their low spawning success as females may be offset by their earlier sex change to become a dominant male. We suggest that changing harems has developed as a life history tactic in high-density conditions where females, in a fish whose sex is socially controlled, compete to become male.

Gonadal investment of young males in two blenniid fishes with alternative mating tactics

The males of two blenniid species which exhibited alternative life history tactics and matured in their first year of life varied in size distribution within the age class and in behaviour. Salaria pavo were the smaller fish of the age class and behaved as sneaker males whereas Parablennius sanguinolentus parvicornis were the larger fish and behaved as satellites.

Analysis of Daily Growth Patterns in Young-of-Year Male Dwarf Surfperch (Embiotocidae:Micrometrus minimus) Suggests Alternative Tactics: Breed or Grow after Birth

Abstract Discontinuous variation in daily growth patterns suggests that there are alternative life-history tactics among males of a coastal fish species. Male dwarf perch are known to be mature and reproductively active at birth, exhibiting a high level of material and behavioral expenditure on breeding early in life. Males experience a substantial cost of reproduction in reduced early growth and survival relative to females. Through analysis of daily growth increments in otoliths, we showed that young-of-year males from two populations exhibit a polymorphism in daily growth patterns. A distinctive episode of narrow growth increments and slow growth punctuated the summertime growth record of some males, whereas increment widths were more uniform and growth was more rapid in other males. Discriminant function analysis revealed that features of the daily growth record varied discontinuously, falling into two distinct groups. Early-born males were more likely to exhibit the slow growth pattern, and late-born...

Life history pattern of the endangered Valencia toothcarp, Valencia hispanica (Actinopterygii: Valenciidae) and its implications for conservation

The life history pattern of the most northern population of an endangered endemic fish from the Iberian Peninsula, Valencia hispanica, was studied in Catalonia. Maximum observed ages were 4+ in females, and 3+ in males. The seasonal growth period started in June and continued until October. Females lived longer and reached larger sizes than males. The largest sizes found were 71 mm versus 67 mm for females and males, respectively. V. hispanica is a multiple spawner that releases small batches of oocytes (varying from 10 to 30) between April and July. The release of oocytes is greatest in May and June. After reproduction, the number of parental individuals decreased. The relationships between fecundity (F) and total length (L t , mm), total weight (W t , g) and gonad weight (W g , g), were: F = 15.735 L t -- 432.91; F = 111.70 W t + 101.17; F = 717.36 W g + 220.80. To examine the drastic regression of this species, its life history tactics were compared with those of another protected endemic cyprinodontid species (Aphanius iberus) which still inhabits areas once occupied by the two species. The biology of the Valencia toothcarp is characterised by slow growth, low reproductive effort, relatively late maturity, high longevity and multiple spawning. This seems to be an inappropriate life history strategy for small fish species in unstable environments with high human pressure, such as Mediterranean estuaries (where the species was once abundant) which are characterised by high, variable or unpredictable adult mortality. Some conservation measures and suggestions for a recovery programme are discussed.

Evolution of Strategies to Stay in the Game

Life-history evolution is a complex process. Life-history theory covers the fundamental level of the process, the evolution of life-history traits. Life-history traits interact; those coevolving as a response to the same selection pressure form life-history tactics. Top level of the hierarchy, life-history strategy, is formed by genetically interconnected tactics. Our aim is to expand the traditional view to life-history evolutionby considering what boundary conditions a successful life-history strategy has to fulfil. We claim that the most fundamental condition successful strategies have to meet is to minimize the risk of evolutionary failure. Here the risk of failure refers to failure in transferring practitioners of the strategy to the next time point, either through survival, or by reproduction. We make an attempt to classify types of risks as they lead to evolutionary failure, and discuss how risk minimization ideas may be approached empirically. We conclude that understanding how traits evolve may not cover all aspects of how strategies evolve. We emphasize that bookkeeping ofthe actual causes of failure might help in developing life-history theory that uses causes of selection to predict responses to selection.