Search results for "Plastic"
showing 10 items of 7296 documents
No evidence of an immune adjustment in response to a parasitoid threat in Lobesia botrana larvae.
2017
5 pages; International audience; Immune function is a key determinant of an organism's fitness, and natural insect populations are highly variable for this trait, mainly due to environmental heterogeneity and pathogen diversity. We previously reported a positive correlation between infection prevalence by parasitoids and host immunity in natural populations of the vineyard pest Lobesia botrana. Here, we tested whether this correlation reflects a plastic adjustment of host immunity in response to the local presence of parasites. To this end, we measured immunity of non-parasitized L. botrana larvae exposed, respectively, to one of the two most common species of parasitoids in vineyards, over…
Assortative pairing for boldness and consequences for reproductive success in Montagu’s harrier
2021
Abstract Behavioural combination within pairs depending on personality and plasticity might influence reproductive success. However, studies testing this hypothesis are rare, especially in the case of monogamous species with bi-parental care in which the sexes exhibit different behavioural roles. In this study, we investigated the pairing patterns for both boldness and boldness plasticity in Montagu’s harriers (Circus pygargus), a species with sex-specific care, and the consequences for their reproductive success. We measured individual boldness and plasticity for both sexes, and we assessed the pairing pattern in the Montagu’s harrier population for these two traits. We calculated four ind…
Effects of photoperiod on life-history and thermal stress resistance traits across populations of Drosophila subobscura
2019
Introduction Organisms use environmental cues to match their phenotype with the future availability of resources and environmental conditions. Changes in the magnitude and frequency of environmental cues such as photoperiod and temperature along latitudes can be used by organisms to predict seasonal changes. While the role of temperature variation on the induction of plastic and seasonal responses is well established, the importance of photoperiod for predicting seasonal changes is less explored. Materials and methods Here we studied changes in life‐history and thermal stress resistance traits in Drosophila subobscura in response to variation in photoperiod (6:18, 12:12 and 18:6 light:dark …
On the use of Persian gum for the development of antiviral edible coatings against murine norovirus of interest in blueberries.
2021
In the last decades, berries have been identified as important vehicles for the transmission of foodborne viruses and different strategies are being explored to eliminate or reduce viral contamination in these fruits. The aim of this work was to develop novel edible coatings with antiviral properties for inactivating and reducing murine norovirus (MNV). Firstly, the effect of gelatin (G) addition on Persian gum (PG) films was studied in terms of microstructural, mechanical, optical, and water barrier properties. The following PG:G ratios were considered: 100:0, 75:25, 50:50, 25:75, and 0:100. Microstructure analysis revealed the compatibility of both hydrocolloids since no phase separation …
Can phthalates move into the eggs of the loggerhead sea turtle Caretta caretta? The case of the nests on the Linosa Island in the Mediterranean Sea
2021
During the monitoring of Caretta caretta nests on the island of Linosa, 30 unhatched eggs from four nests were collected to study the presence of phthalates in their three components (shell, yolk, and albumen). Four phthalates, namely diethyl (DEP), dibutyl (DBP), di-(2-ethylhexyl) (DEHP), and dioctyl (DOTP) phthalic acid esters (PAE), which are widely used as additives in plastics, were detected in all egg components. The most frequently found phthalate was DBP, followed by DEHP in eggshell and yolk. Dimethyl- (DMP) and butylbenzyl-phthalate (BBP) were below the limits of detection for all samples. The high total phthalate recorded in the yolk suggests that contamination could arise by vit…
The influence of thermal extremes on coral reef fish behaviour in the Arabian/Persian Gulf
2019
Despite increasing environmental variability within marine ecosystems, little is known about how coral reef fish species will cope with future climate scenarios. The Arabian/Persian Gulf is an extreme environment, providing an opportunity to study fish behaviour on reefs with seasonal temperature ranges which include both values above the mortality threshold of Indo-Pacific reef fish, and values below the optimum temperature for growth. Summer temperatures in the Gulf are comparable to those predicted for the tropical ocean by 2090–2099. Using field observations in winter, spring and summer, and laboratory experiments, we examined the foraging activity, distance from refugia and resting tim…
Heat hardening capacity in Drosophila melanogaster is life stage-specific and juveniles show the highest plasticity
2019
Variations in stress resistance and adaptive plastic responses during ontogeny have rarely been addressed, despite the possibility that differences between life stages can affect species' range margins and thermal tolerance. Here, we assessed the thermal sensitivity and hardening capacity of Drosophila melanogaster across developmental stages from larval to the adult stage. We observed strong differences between life stages in heat resistance, with adults being most heat resistant followed by puparia , pupae and larvae . The impact of heat hardening (1 h at 35°C) on heat resistance changed during ontogeny, with the highest positive effect of hardening observed in puparia and pupae and the …
Phenotypic plasticity in growth and fecundity induced by strong population fluctuations affects reproductive traits of female fish
2016
Fish are known for their high phenotypic plasticity in life-history traits in relation to environmental variability, and this is particularly pronounced among salmonids in the Northern Hemisphere. Resource limitation leads to trade-offs in phenotypic plasticity between life-history traits related to the reproduction, growth, and survival of individual fish, which have consequences for the age and size distributions of populations, as well as their dynamics and productivity. We studied the effect of plasticity in growth and fecundity of vendace females on their reproductive traits using a series of long-term incubation experiments. The wild parental fish originated from four separate populat…
Personalities influence spatial responses to environmental fluctuations in wild fish
2017
Abstract Although growing evidence supports the idea that animal personality can explain plasticity in response to changes in the social environment, it remains to be tested whether it can explain spatial responses of individuals in the face of natural environmental fluctuations. This is a major challenge in ecology and evolution as spatial dynamics link individual‐ and population‐level processes.In this study, we investigated the potential of individual personalities to predict differences in fish behaviour in the wild. Specifically, our goal was to answer if individual differences in plasticity of space use to sea surface temperature could be explained by differences in personality along …
Honeybees prefer novel insect-pollinated flower shapes over bird-pollinated flower shapes
2019
AbstractPlant–pollinator interactions have a fundamental influence on flower evolution. Flower color signals are frequently tuned to the visual capabilities of important pollinators such as either bees or birds, but far less is known about whether flower shape influences the choices of pollinators. We tested European honeybee Apis mellifera preferences using novel achromatic (gray-scale) images of 12 insect-pollinated and 12 bird-pollinated native Australian flowers in Germany; thus, avoiding influences of color, odor, or prior experience. Independent bees were tested with a number of parameterized images specifically designed to assess preferences for size, shape, brightness, or the number…