Population effects and changes in life history traits in relation to phase transitions induced by long-term fishery harvesting: European hake (Merluccius merluccius) off the Balearic Islands

2009 ◽  
Vol 66 (8) ◽  
pp. 1355-1370 ◽  
Author(s):  
Manuel Hidalgo ◽  
Enric Massutí ◽  
Beatriz Guijarro ◽  
Joan Moranta ◽  
Lorenzo Ciannelli ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Size Structure ◽  
Sharp Decrease ◽  
Mesh Size ◽  
Population Level ◽  
Balearic Islands ◽  
Catch Per Unit Effort ◽  
Merluccius Merluccius ◽  
European Hake

In 1980 and 1995, the European hake ( Merluccius merluccius ) population off the Balearic Islands (northwestern Mediterranean) underwent changes at both the individual level and the population level. There was a sharp decrease in abundance that coincided with a change in the seasonal catch-per-unit-effort pattern in 1980. A new population scenario emerged after 1980 characterized by an increase in the intrinsic growth rate and a decrease in carrying capacity; however, catchability remained the same. An age-structure truncation could have caused these changes, making the population more dependent on year-to-year recruitment. A change in size structure also occurred in 1995, which was evidenced by a sudden decrease in the mean length-at-age (L) and abundance of recruits and a change in the density-dependent effect on recruits. As the Mediterranean trawl fishery mainly harvests recruits and juveniles and fishery harvesting induces adaptive changes in life history traits, the sharp decrease in L of recruits could be explained as a growth reduction due to the selective pressure to stay under mesh size for longer and thus maximize survival until reproduction. These individual and population transitions explain the changes in the response to the environmental forcing observed in the European hake off the Balearic Islands.

scholarly journals Intraspecific phenotypic variation in life history traits ofDaphnia galeatapopulations in response to fish kairomones

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5746 ◽  
Author(s):  
Verena Tams ◽  
Jennifer Lüneburg ◽  
Laura Seddar ◽  
Jan-Phillip Detampel ◽  
Mathilde Cordellier
Keyword(s):  
Life History ◽  
Environmental Change ◽  
Phenotypic Variation ◽  
Life History Traits ◽  
Common Garden ◽  
Population Level ◽  
Geometric Morphometric ◽  
Fish Kairomones ◽  
Geometric Morphometric Analysis ◽  
Clonal Lines

Phenotypic plasticity is the ability of a genotype to produce different phenotypes depending on the environment. It has an influence on the adaptive potential to environmental change and the capability to adapt locally. Adaptation to environmental change happens at the population level, thereby contributing to genotypic and phenotypic variation within a species. Predation is an important ecological factor structuring communities and maintaining species diversity. Prey developed different strategies to reduce their vulnerability to predators by changing their behaviour, their morphology or their life history. Predator-induced life history responses inDaphniahave been investigated for decades, but intra-and inter-population variability was rarely addressed explicitly. We addressed this issue by conducting a common garden experiment with 24 clonal lines of EuropeanDaphnia galeataoriginating from four populations, each represented by six clonal lines. We recorded life history traits in the absence and presence of fish kairomones. Additionally, we looked at the shape of experimental individuals by conducting a geometric morphometric analysis, thus assessing predator-induced morphometric changes. Our data revealed high intraspecific phenotypic variation within and between fourD. galeatapopulations, the potential to locally adapt to a vertebrate predator regime as well as an effect of the fish kairomones on morphology ofD. galeata.

scholarly journals Age estimation, growth and maturity of the European hake (Merluccius merluccius (Linnaeus, 1758)) from Iberian Atlantic waters

2003 ◽  
Vol 60 (5) ◽  
pp. 1086-1102 ◽  
Author(s):  
C Piñeiro ◽  
M Saínza
Keyword(s):  
Life History ◽  
Age Estimation ◽  
Growth Parameters ◽  
Grey Literature ◽  
Von Bertalanffy ◽  
Merluccius Merluccius ◽  
Consistent Manner ◽  
The Mean ◽  
First Maturity ◽  
European Hake

Abstract Difficulties in age estimation for hake (Merluccius merluccius) have hampered the assessment of stocks. Here, we describe new, agreed ageing criteria based on the interpretation of the pattern of otolith growth. Improved estimates of von Bertalanffy growth parameters, and new estimates of maturity ogive parameters and length–weight relationships for European hake from Iberian Atlantic waters are presented. The results came from a study carried out during 1996–1997 and provide the first published account of the main life history traits of Southern stock hake. von Bertalanffy growth parameters of males were L∞ = 70cm, K = 0.18 year−1, and t0=−0.97 year, and those of females were L∞ = 89cm, K = 0.13 year−1, and t0 = −1.15 year. Growth of sexes differed from age 3 onwards, with females being on average larger and heavier than males. The estimated total length (L, cm)–total weight (W, g) relationships were W=0.0132135L2.8134246 for males and W=0.0086471L2.942563 for females. Spawning took place from December to May with a peak in February. The mean length and age at first maturity were 32.8 cm at 2.5 years for males and 45 cm at 4.4 years for females. Application of new ageing criteria showed that otolith sections may be used to determine ages up to 5 years in a consistent manner. These results indicate that hake of the Southern stock grow at higher rates and mature earlier than previously considered. Summaries of hake's life history parameters from other marine regions are also presented in order to make information that belongs largely to the grey literature available.

Religion and fertility patterns: comparison of life history traits in Catholics and Protestants, Hallstatt (Austria) 1733–1908

2020 ◽  
pp. 1-14
Author(s):  
Alina Gavrus-Ion ◽  
Torstein Sjøvold ◽  
Miguel Hernández ◽  
Rolando González-José ◽  
Neus Martínez-Abadías ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Population Level ◽  
Childhood Mortality ◽  
Social Changes ◽  
Number Of Children ◽  
First Child ◽  
The Family ◽  
Sanitary Conditions ◽  
Age At Birth

Abstract Catholicism and Protestantism have different ways of promoting the family unit that could influence survival and fertility at a population level. Parish records in the Austrian village of Hallstatt allowed the reconstruction of Catholic and Protestant genealogies over a period of 175 years (1733–1908) to evaluate how religion and social changes affected reproduction and survival. Life history traits such as lifespan beyond 15 years, number of offspring, reproductive span, children born out of wedlock and child mortality were estimated in 5678 Catholic and 3282 Protestant individuals. The interaction of sex, time and religion was checked through non-parametric factorial ANOVAs. Religion and time showed statistically significant interactions with lifespan >15 years, number of offspring and age at birth of first child. Protestants lived longer, had a larger reproductive span and an earlier age at birth of first child. Before the famine crisis of 1845–1850, Protestants showed lower values of childhood mortality than Catholics. Comparison of the number of children born out of wedlock revealed small differences between the two religions. Religion influenced reproduction and survival, as significant differences were found between Catholics and Protestants. This influence could be explained in part by differential socioeconomic characteristics, since Protestants may have enjoyed better living and sanitary conditions in Hallstatt.

scholarly journals Population declines of tuna and relatives depend on their speed of life

2015 ◽  
Vol 282 (1811) ◽  
pp. 20150322 ◽  
Author(s):  
M. J. Juan-Jordá ◽  
I. Mosqueira ◽  
J. Freire ◽  
N. K. Dulvy
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Population Level ◽  
Maximum Size ◽  
Latitudinal Gradients ◽  
Fishing Mortality ◽  
Population Declines ◽  
Wide Range ◽  
Exploitation Status

Larger-bodied species in a wide range of taxonomic groups including mammals, fishes and birds tend to decline more steeply and are at greater risk of extinction. Yet, the diversity in life histories is governed not only by body size, but also by time-related traits. A key question is whether this size-dependency of vulnerability also holds, not just locally, but globally across a wider range of environments. We test the relative importance of size- and time-related life-history traits and fishing mortality in determining population declines and current exploitation status in tunas and their relatives. We use high-quality datasets of half a century of population trajectories combined with population-level fishing mortalities and life-history traits. Time-related traits (e.g. growth rate), rather than size-related traits (e.g. maximum size), better explain the extent and rate of declines and current exploitation status across tuna assemblages, after controlling for fishing mortality. Consequently, there is strong geographical patterning in population declines, such that populations with slower life histories (found at higher cooler latitudes) have declined most and more steeply and have a higher probability of being overfished than populations with faster life histories (found at tropical latitudes). Hence, the strong, temperature-driven, latitudinal gradients in life-history traits may underlie the global patterning of population declines, fisheries collapses and local extinctions.

scholarly journals Can Invasiveness in Freshwater Fishes Be Predicted From Life-History Traits?

2020 ◽  
Vol 8 ◽  
Author(s):  
Gordon H. Copp ◽  
Michael G. Fox
Keyword(s):  
Life History ◽  
Life History Traits ◽  
A Priori ◽  
Secondary Data ◽  
Freshwater Fishes ◽  
Lepomis Gibbosus ◽  
Catch Per Unit Effort ◽  
Black Bullhead ◽  
Non Invasive ◽  
Western Asia

We review a model we developed in 2007 to predict the invasion potential of an introduced population, based on the relationship between juvenile growth (mean total length at age 2) and mean age-at-maturity, and test the model with data from 75 non-native populations of pumpkinseed Lepomis gibbosus in nine countries of Europe and western Asia. The database used to construct the model was derived from a mix of primary and secondary data collected between 1981 and 2016. Based on number of specimens collected or catch-per-unit-effort data, and/or comments by the original authors, populations were classified a priori as “invasive” or “non-invasive.” The plot of the proposed model placed populations in three invasiveness categories (non-invasive, transitional, invasive). Of those predicted by the model to be invasive, only 57% were correct with regard to their a priori classification, a result that was not statistically significant. For populations predicted by the model to be non-invasive, 70% were correct with regard to their a priori classification when “transitional” were grouped with non-invasive (P = 0.0024), and 64% were correct when “transitional” were excluded from the test (P = 0.12). Applications of the model to two other non-native freshwater fishes (black bullhead Ameiurus melas and crucian carp Carassius carassius) are also discussed. The lack of stronger statistical support for the model may have been the result of using life-history traits from the populations after they were introduced, as the source populations were unknown, as well as to shortcomings in the dataset that could affect a priori and modeled classifications. We conclude that such life-history models can be useful for predicting invasiveness status in non-native freshwater fishes, though the basis of the predictions, statistical or heuristic, will depend on the size and quality of the underlying life-history database.

scholarly journals Effects of density dependent larval competition on the life history traits of Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

2017 ◽  
Vol 49 (1) ◽  
pp. 97 ◽  
Author(s):  
Sampa Banerjee ◽  
Soujita Pramanik ◽  
Soumyajit Banerjee ◽  
Goutam K. Saha ◽  
Gautam Aditya
Keyword(s):  
Life History ◽  
Aedes Aegypti ◽  
Life History Traits ◽  
Population Level ◽  
Competitive Interactions ◽  
Pupal Weight ◽  
Larval Competition ◽  
Density Dependent ◽  
Geographical Regions ◽  
F2 Generation

Consequences of larval competition at the population level provide explanation for the differences in relative abundance of <em>Aedes aegypti</em> and <em>Aedes</em> <em>albopictus</em> in different geographical regions. The outcome of competition is assessed through the estimates of the life history traits as a response to varying density and resource available for larval development. In the present study, variations in the life history traits due to density-dependent intra- and inter- specific competition involving <em>A. aegypti</em> and <em>A. albopictus</em> were assessed following the minimalist model. The instar-I larvae (0-day old F2 generation) of both <em>Aedes</em> species were reared to the adult stages using the initial rearing density of 1, 2, 4 and 6 (individuals/10ml) in multiple replicates. The age at pupation, pupal weight, adult weight and adult wing length of the individuals were considered as the response variables and surrogates of estimating the competitive interactions. Density dependent variations in the competitive interactions were evident for both the mosquitoes with reference to the selected life history traits. In <em>A. aegypti,</em> the life history traits varied with the levels of competition, which was not observed for <em>A. albopictus</em>. Although the density levels considered in the present instance were lower than in earlier studies, the observations were similar, with <em>A. albopictus</em> being competitively superior. It appears that irrespective of the density levels, interspecific competition affects <em>A. aegypti</em> and thus may bear population level consequences and overall abundance in the areas where both species are present.

Life history traits of the free-living nematode, Plectus acuminatus Bastian, 1865, and responses to cadmium exposure

Nematology ◽  
2017 ◽  
Vol 19 (6) ◽  
pp. 645-654 ◽  
Author(s):  
Bianca Kreuzinger-Janik ◽  
Marvin Brinke ◽  
Walter Traunspurger ◽  
Nabil Majdi
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Population Level ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Free Living ◽  
Energy Flows ◽  
Free Living Nematode ◽  
Hanging Drop Method ◽  
Standard Life

Free-living nematodes are ubiquitous and play an essential role in ecosystems. However, little is known about their standard life history traits (LHTs), which limits their inclusion in estimations of energy flows and carrying capacities of ecosystems, as well as in modelling population-level responses to toxicants. Thus, we used the hanging-drop method to measure LHTs of Plectus acuminatus with and without exposure to cadmium (2 mg l−1). In controls, the mean lifespan was 68 days and the maximum 114 days. Individuals laid eggs on average 19 days after hatching, while production of offspring peaked at 37 days. Plectus acuminatus individuals were very fertile, producing on average 848 juveniles. Population growth rate of 0.19 was estimated for the control cohort leading to an average population doubling time of 3.65 days. Exposure to cadmium reduced mean lifespan by 62% and affected reproduction as only 22% of individuals produced offspring, leading to a total fertility rate 85% lower than in controls.

scholarly journals Personality and the emergence of the pace-of-life syndrome concept at the population level

2010 ◽  
Vol 365 (1560) ◽  
pp. 4051-4063 ◽  
Author(s):  
Denis Réale ◽  
Dany Garant ◽  
Murray M. Humphries ◽  
Patrick Bergeron ◽  
Vincent Careau ◽  
...  
Keyword(s):  
Life History ◽  
Personality Traits ◽  
Related Species ◽  
Life History Traits ◽  
Population Level ◽  
Closely Related Species ◽  
Ecological Conditions ◽  
Pace Of Life ◽  
Physiological Differences ◽  
Personality Studies

The pace-of-life syndrome (POLS) hypothesis specifies that closely related species or populations experiencing different ecological conditions should differ in a suite of metabolic, hormonal and immunity traits that have coevolved with the life-history particularities related to these conditions. Surprisingly, two important dimensions of the POLS concept have been neglected: (i) despite increasing evidence for numerous connections between behavioural, physiological and life-history traits, behaviours have rarely been considered in the POLS yet; (ii) the POLS could easily be applied to the study of covariation among traits between individuals within a population. In this paper, we propose that consistent behavioural differences among individuals, or personality, covary with life history and physiological differences at the within-population, interpopulation and interspecific levels. We discuss how the POLS provides a heuristic framework in which personality studies can be integrated to address how variation in personality traits is maintained within populations.

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