scholarly journals Life history traits of the exotic freshwater snail Melanoides tuberculata Müller, 1774 (Gastropoda, Thiaridae), and its sensitivity to common stressors in freshwaters

2020 ◽  
Vol 32 ◽  
Author(s):  
Denise Tieme Okumura ◽  
Odete Rocha
Keyword(s):  
Life History ◽  
Growth Curve ◽  
Life History Traits ◽  
Freshwater Snail ◽  
Individual Growth ◽  
Toxic Substances ◽  
Melanoides Tuberculata ◽  
Laboratory Conditions ◽  
Individual Growth Curve ◽  
The Individual

Abstract: Aim In the present study has analyzed several aspects of the life history traits of Melanoides tuberculata, an exotic species, under laboratory conditions, and its response to some stressors has also been applied. Methods Sensitivity to two toxic substances was tested. The mollusks were collected and cultured in the laboratory under controlled conditions of temperature of 25 ± 1 °C and ad libitum food regime. Growth rates and biomass were experimentally obtained and the individual growth curve obtained. Results The experiment lasted 287 days and the maximum shell lengths registered was 11.67 mm. The growth curve indicated a rate of 3.98 year-1 and a maximum theoretical length of 10.61 mm. The mean post-embrionary development time until first reproduction was 275 days and the size of the primipara was 10.13 mm. An accelerated growth of juveniles was observed with fast increase in the shell length until sexual maturity, but growth rate decreased afterwards as more energy was devoted to reproduction. Under the combination of 25 °C and fed on alternate days, M. tuberculata had a slow growth and a long-life expectancy under laboratory conditions. The tolerance of this mollusk to temperature as a stressor ranged between 16 °C and 37 °C, being the optimum temperature situated between 29 °C and 34 °C. The LC(I)50-24h for reference substances were: 0.70 g L-1 for KCl and 9.05 g L-1 for NaCl. Conclusion Based on these results, we can conclude that M. tuberculata is a species tolerant to temperature and salinity, what partially explains to accordance to its wide and rapid dispersion throughout tropical waters.

Production of Larvae of Phyllobius piri L. (Col. Curculionidae) in an Abandoned Field

1973 ◽  
Vol 4 (1) ◽  
pp. 21-29 ◽  
Author(s):  
S. Larsson ◽  
T. Persson ◽  
U. Lohm ◽  
B. Axelsson
Keyword(s):  
Life History ◽  
Life Table ◽  
Growth Curve ◽  
Individual Growth ◽  
Abandoned Field ◽  
Individual Growth Curve ◽  
History Of ◽  
The Individual

AbstractThe abundance of the larvae of Phyllobius piri L. and P. viridicollis F. (Col. Curculionidae) was investigated in an abandoned field in central Sweden. On the basis of the individual growth curve and the life table of the larvae the production of P. piri was calculated to be 4.6 ± I.9 g dw per m2 or 25 ± II kcal per m2 (mean ± 95 per cent c.i.). The population of the hibernating pupae of P. piri was about 500 per m2 during three successive years. During the same period the abundance of hibernating larvae of P. viridicollis was I00-250 per m2. Notes are given on the life history of the two species. The larvae are described by B. Lekander in an appendix.

The influence of self-fertilization and pairing on life-history traits in the freshwater snail Bulinus forskalii (Gastropoda, Planorbidae)

Acta Tropica ◽  
2000 ◽  
Vol 76 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Flobert Njiokou ◽  
Jean Bosco Mouafo ◽  
Félicité Teukeng ◽  
Thomas Njine ◽  
Albert Same Ekobo ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Freshwater Snail ◽  
Self Fertilization

scholarly journals Life-history variation of drosophila subobscura under lead pollution depends on population history

Genetika ◽  
2014 ◽  
Vol 46 (3) ◽  
pp. 693-703 ◽  
Author(s):  
Bojan Kenig ◽  
Aleksandra Patenkovic ◽  
Marko Andjelkovic ◽  
Marina Stamenkovic-Rada
Keyword(s):  
Heavy Metal ◽  
Life History ◽  
Metal Contamination ◽  
Life History Traits ◽  
Heavy Metal Contamination ◽  
Developmental Time ◽  
Drosophila Subobscura ◽  
Life History Variation ◽  
Laboratory Conditions ◽  
Coefficients Of Variation

Contamination represents environmental stress that can affect genetic variability of populations, thus influencing the evolutionary processes. In this study, we evaluate the relationship between heavy metal contamination (Pb) and phenotypic variation, assessed by coefficients of variation (CV) of life-history traits. To investigate the consequences of population origin on variation of life history traits in Drosophila subobscura in response to different laboratory conditions we compared populations from relatively polluted and unpolluted environments. Prior to experiment, flies from natural populations were reared for two generations in standard Drosophila laboratory conditions. Afterwards, all flies were cultured on three different media: one medium without lead as the control, and the other two with different concentrations of lead. Coefficients of variation (CV) of life- history traits (fecundity, egg-to-adult viability and developmental time) were analyzed on flies sampled in generations F2, F5 and F8 from these three groups. In later generations samples from both polluted and unpolluted environments showed the increased fecundity variation on media with lead. This increase is expressed more in population from unpolluted environment. On contrary, population from unpolluted environment had increased variation of developmental time in earlier, F2 generation, compared to the population from polluted environment. Our results showed that the response to heavy metal contamination depends on the evolutionary history of the populations regarding habitat pollution.

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 Early swelling response to phytohemagglutinin is lower in older toads

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6104 ◽  
Author(s):  
Francisco Javier Zamora-Camacho ◽  
Mar Comas
Keyword(s):  
Immune Response ◽  
Time Series ◽  
Life History ◽  
Life History Traits ◽  
Area Under The Curve ◽  
Older Individuals ◽  
Innate Response ◽  
Early Immune Response ◽  
The Individual ◽  
Epidalea Calamita

The effects of age on performance of life-history traits are diverse, but a common outcome is senescence, an irreversible deterioration of physical and physiological capabilities of older individuals. Immune response is potentially bound to senescence. However, little is known about immune response ageing in amphibians. In this work, we test the hypothesis that amphibian early immune response is reduced in older individuals. To this end, we captured adult natterjack toads (Epidalea calamita) and inoculated them with phytohemagglutinin, an innocuous protein that triggers a skin-swelling immune response whose magnitude is directly proportional to the ability of the individual to mount an immune response. We measured early swelling immune response (corresponding to an innate-response stage) hourly, for six hours, and we calculated the area under the curve (AUC) for each individual’s time series, as a measure of immune response magnitude incorporating time. We estimated toad age by means of phalanx skeletochronology. Swelling and AUC decreased with age. Therefore, in accordance with our predictions, early immune response seems subject to senescence in these toads. Reduced ability to get over infections due to senescence of immune respose might be—together with a worse functioning of other organs and systems—among the causes of lower survival of older specimens.

scholarly journals Individual variability in life-history traits drives population size stability

2012 ◽  
Vol 58 (2) ◽  
pp. 358-362 ◽  
Author(s):  
Ned A. Dochtermann ◽  
C. M. Gienger
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Individual Variability ◽  
Population Variation ◽  
Sceloporus Undulatus ◽  
Natural Systems ◽  
Size Stability ◽  
Population Sizes ◽  
The Individual ◽  
Dynamics Of Populations

Abstract Understanding how population sizes vary over time is a key aspect of ecological research. Unfortunately, our understanding of population dynamics has historically been based on an assumption that individuals are identical with homogenous life-history properties. This assumption is certainly false for most natural systems, raising the question of what role individual variation plays in the dynamics of populations. While there has been an increase of interest regarding the effects of within population variation on the dynamics of single populations, there has been little study of the effects of differences in within population variation on patterns observed across populations. We found that life-history differences (clutch size) among individuals explained the majority of the variation observed in the degree to which population sizes of eastern fence lizards Sceloporus undulatus fluctuated. This finding suggests that differences across populations cannot be understood without an examination of differences at the level of a system rather than at the level of the individual [Current Zoology 58 (2): 358–362, 2012].

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