scholarly journals Life stages differ in plasticity to temperature fluctuations and uniquely contribute to adult phenotype in Onthophagus taurus dung beetles

2020 ◽  
Vol 223 (20) ◽  
pp. jeb227884 ◽  
Author(s):  
Amanda W. Carter ◽  
Kimberly S. Sheldon

ABSTRACTAdaptive thermal plasticity allows organisms to adjust their physiology to cope with fluctuating environments. However, thermal plasticity is rarely studied in response to thermal variability and is often measured in a single life stage. Plasticity in response to thermal variability likely differs from responses to constant temperature or acute stress. In addition, life stages likely differ in their plasticity, and responses in one stage may be affected by the experiences in a previous stage. Increasing the resolution with which we understand thermal plasticity in response to thermal variation across ontogeny is crucial to understanding how organisms cope with the thermal variation in their environment and to estimating the capacity of plasticity to mitigate costs of rapid environmental change. We wanted to know whether life stages differ in their capacity for thermal plasticity under temperature fluctuations. We reared Onthophagus taurus dung beetles in either low or high temperature fluctuation treatments and quantified thermal plasticity of metabolism of pupae and adults. We found that adults were thermally plastic and pupae were not. Next, we tested whether the plasticity observed in the adult life stage was affected by the thermal conditions during development. We again used low and high temperature fluctuation treatments and reared individuals in one condition through all egg to pupal stages. At eclosion, we switched half of the individuals in each treatment to the opposite fluctuation condition and, later, measured thermal plasticity of metabolism in adults. We found that temperature conditions experienced during the adult stage, but not egg to pupal stages, affect adult thermal plasticity. However, temperature fluctuations during development affect adult body size, suggesting that some aspects of the adult phenotype are decoupled from previous life stages and others are not. Our data demonstrate that life stages mount different responses to temperature variability and uniquely contribute to the adult phenotype. These findings emphasize the need to broadly integrate the life cycle into studies of phenotypic plasticity and physiology; doing so should enhance our ability to predict organismal responses to rapid global change and inform conservation efforts.

Author(s):  
Charlotte Scott

Beginning with an exploration of the role of the child in the cultural imagination, Chapter 1 establishes the formative and revealing ways in which societies identify themselves in relation to how they treat their children. Focusing on Shakespeare and the early modern period, Chapter 1 sets out to determine the emotional, symbolic, and political registers through which children are depicted and discussed. Attending to the different life stages and representations of the child on stage, this chapter sets out the terms of the book’s enquiry: what role do children play in Shakespeare’s plays; how do we recognize them as such—age, status, parental dynamic—and what are the effects of their presence? This chapter focuses on how the early moderns understood the child, as a symbolic figure, a life stage, a form of obligation, a profound bond, and an image of servitude.


2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Fallon Fowler ◽  
Tashiana Wilcox ◽  
Stephanie Orr ◽  
Wes Watson

Abstract Understanding collection methodologies and their limitations are essential when targeting specific arthropods for use in habitat restoration, conservation, laboratory colony formation, or when holistically representing local populations using ecological surveys. For dung beetles, the most popular collection methodology is baited traps, followed by light traps and unbaited flight-intercept traps during diversity surveys. A less common collection method, flotation, is assumed to be laborious and messy, and so only a handful of papers exist on its refinement and strengths. Our purpose was threefold: First, we tested the recovery and survival rates of Labarrus (=Aphodius) pseudolividus (Balthasar) and Onthophagus taurus (Schreber) when floating beetle-seeded dung pats to determine potential collection and safety issues. We collected 72.4 and 78% of the seeded L. pseudolividus and O. taurus, respectively, with >95% survival rating. Second, we developed a flotation-sieving technique that enables users to rapidly collect and passively sort dung beetles with less time and effort. Specifically, we often collected 50–100 g of wild dung beetles within a couple of hours of gathering dung and sorted them in a couple more by allowing dung beetles to sort themselves by size within a series of sieves; Third, we reviewed flotation-based advantages and disadvantages in comparison to other methodologies.


2017 ◽  
Vol 27 (2) ◽  
pp. 74-83 ◽  
Author(s):  
L. Felipe Daibes ◽  
Talita Zupo ◽  
Fernando A.O. Silveira ◽  
Alessandra Fidelis

AbstractInformation from a field perspective on temperature thresholds related to physical dormancy (PY) alleviation and seed resistance to high temperatures of fire is crucial to disentangle fire- and non-fire-related germination cues. We investigated seed germination and survival of four leguminous species from a frequently burned open Neotropical savanna in Central Brazil. Three field experiments were conducted according to seed location in/on the soil: (1) fire effects on exposed seeds; (2) fire effects on buried seeds; and (3) effects of temperature fluctuations on exposed seeds in gaps and shaded microsites in vegetation. After field treatments, seeds were tested for germination in the laboratory, together with the control (non-treated seeds). Fire effects on exposed seeds decreased viability in all species. However, germination of buried Mimosa leiocephala seeds was enhanced by fire in an increased fuel load treatment, in which we doubled the amount of above-ground biomass. Germination of two species (M. leiocephala and Harpalyce brasiliana) was enhanced with temperature fluctuation in gaps, but this condition also decreased seed viability. Our main conclusions are: (1) most seeds died when exposed directly to fire; (2) PY could be alleviated during hotter fires when seeds were buried in the soil; and (3) daily temperature fluctuations in gaps also broke PY of seeds on the soil surface, so many seeds could be recruited or die before being incorporated into the soil seed banks. Thus seed dormancy-break and germination of legumes from Cerrado open savannas seem to be driven by both fire and temperature fluctuations.


2011 ◽  
Vol 13 (3) ◽  
pp. 333-340 ◽  
Author(s):  
Stephanie Sobek ◽  
Arun Rajamohan ◽  
Daniel Dillon ◽  
Robert C. Cumming ◽  
Brent J. Sinclair

2019 ◽  
Vol 97 (1) ◽  
pp. 35 ◽  
Author(s):  
Víctor Abraham Vargas-Vázquez ◽  
Crystian Sadiel Venegas-Barrera ◽  
Arturo Mora-Olivo ◽  
José Guadalupe Martínez-Ávalos ◽  
Eduardo Alanís-Rodríguez ◽  
...  

<p><strong>Background: </strong>The edge effect differentially affects the species in their life stages. We analyzed the environmental conditions associated with the abundance by life stage of four species of timber trees on the edge of a subdeciduous tropical forest.<strong></strong></p><p><strong>Hypothesis:</strong> The edges have higher light incidence and temperature, favorable conditions for the seedlings, so it is expected that the edge will have more abundance of seedlings with respect to the forest interior.</p><p><strong>Species under study:</strong> <em>Bursera simaruba</em> (L.) Sarg.<em>, Cedrela odorata</em> L.<em>, Guazuma ulmifolia </em>Lam.<em>, Lysiloma divaricatum </em>(Jacq.) J.F. Macbr.</p><p><strong>Study site and dates:</strong> Reserva de la Biosfera "El Cielo" (Tamaulipas), Mexico. January-December 2016.</p><p><strong>Methods: </strong>The abundance by life stages and environmental conditions were quantified within the gradient. These variables were correlated, in addition the requirements between stages were contrasted and they were associated with the identified environments.</p><p><strong>Results:</strong> <em>Guazuma ulmifolia</em> showed a negative response to the edge effect, while <em>Cedrela</em> <em>odorata</em> responded positively. The environmental requirements differed between the first life stages and adults. The abundance of the seedlings was associated to conditions of higher light incidence.</p><strong>Conclusions:</strong> Environmental requirements differentially affect each life stage. The abundance of seedlings increases in conditions of higher light incidence, but not in the rest of the stages, except in <em>C. odorata</em>. The loss of cover and the consequent formation of borders can lead to a reduction in the abundance of these species, with economic implications.


2021 ◽  
pp. jeb.229476
Author(s):  
Yu-Wen Chung-Davidson ◽  
Ugo Bussy ◽  
Skye D. Fissette ◽  
Anne M. Scott ◽  
Weiming Li

Pheromonal bile salts are important for sea lampreys (Petromyzon marinus Linnaeus) to complete their life cycle. The synthesis and release of a releaser/primer pheromone 3-keto petromyzonol sulfate (3kPZS) by spermiating males have been well characterized. 3kPZS evokes sexual behaviors in ovulatory females, induces immediate 3kPZS release in spermiating males, and elicits neuroendocrine responses in prespawning adults. Another primer pheromone released by spermiating males, 3-keto allocholic acid (3kACA), antagonizes the neuroendocrine effects of 3kPZS in prespermiating males. However, the effects of 3kACA and 3kPZS on pheromone production in prespawning adults is unclear. To understand the foundation of pheromone production, we examined sea lamprey bile salt levels at different life stages. To investigate the priming effects of 3kACA and 3kPZS, we exposed prespawning adults with vehicle or synthetic 3kACA or 3kPZS. We hypothesized that endogenous bile salt levels were life-stage and sex-dependent, and differentially affected by 3kACA and 3kPZS in prespawning adults. Using ultra-performance liquid chromatography tandem mass spectrometry, we found that sea lampreys contained distinct mixtures of bile salts in the liver and plasma at different life stages. Males usually contained higher amounts of bile salts than females. Petromyzonamine disulfate was the most abundant C27 bile salt and petromyzonol sulfate was the most abundant C24 bile salt. Waterborne 3kACA and 3kPZS exerted differential effects on bile salt production in the liver and gill, their circulation and clearance in the plasma, and their release into water. We conclude that bile salt levels are life-stage and sex-dependent and differentially affected by primer pheromones.


Author(s):  
Yoshihiro Ishikawa ◽  
Yukihiko Okuda ◽  
Naoto Kasahara

In the nuclear power plants, there are many branch pipes with closed-end which are attached vertically to the main pipe. We consider a situation in which the high temperature water is transported in the main pipe, the branch pipe is filled with stagnant water which has lower temperature than the main flow, and the end of the branch pipe is closed. At the branch connection part, it is known that a cavity flow is induced by the shear force of the boundary layer which separates from the leading edge of the branch pipe along the main pipe wall. In cases where the high temperature water penetrates into the branch pipe, there is a possibility that a steep and large temperature gradient field, called “thermal stratification layer” is formed at the boundary between high and low temperature water in the branch pipe. If the thermal stratification layer is formed in a bend pipe, which is used for connecting the vertical branch pipe and to a horizontal pipe, at the same time, the temperature fluctuation by the thermal stratification layer motion occurs, there may cause the thermal stress in the piping material. Furthermore, keeping the piping material under the thermal stress, there might be a possibility of a crack on the surface of the bend pipe. For this reason, the evaluation of the position where the thermal stratification layer reaches is very important during early piping design process. And, deeply understanding regarding the phenomena, is also important. However, because of the complexities of the phenomena, it is difficult to immediately clarify the whole mechanisms of the thermal stress arising due to the temperature fluctuation by the thermal stratification layer change. The complete prediction method for the position of the thermal stratification layer based on the mechanisms that is able to be applied to any piping system, any temperature and any velocity conditions, is also difficult. Therefore, a practical approach is required. The authors attempt to develop the practical estimation method for the thermal stratification layer position using the three-dimensional Navier-Stokes simulation which was based on the Reynolds-average in order to reduce the computational costs. In this paper, three different configurations of the piping were simulated and the simulation results were compared with the experimental results obtained by the other research group.


BMC Zoology ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Helen M. K. O’Neill ◽  
Sarah M. Durant ◽  
Rosie Woodroffe

Abstract Background Habitat loss is a key threat to the survival of many species. Habitat selection studies provide key information for conservation initiatives by identifying important habitat and anthropogenic characteristics influencing the distribution of threatened species in changing landscapes. However, assumptions about the homogeneity of individual choices on habitat, regardless of life stage, are likely to result in inaccurate assessment of conservation priorities. This study addresses a knowledge gap in how animals at different life stages diverge in how they select habitat and anthropogenic features, using a free-ranging population of African wild dogs living in a human-dominated landscape in Kenya as a case study. Using GPS collar data to develop resource selection function and step selection function models, this study investigated differences between second order (selection of home range across a landscape) and third order (selection of habitat within the home range) habitat selection across four life history stages when resource requirements may vary: resident-non-denning, resident-heavily-pregnant, resident-denning and dispersing. Results Wild dogs showed strong second order selection for areas with low human population densities and areas close to rivers and roads. More rugged areas were also generally selected, as were areas with lower percentage tree cover. The strength of selection for habitat variables varied significantly between life stages; for example, dispersal groups were more tolerant of higher human population densities, whereas denning and pregnant packs were least tolerant of such areas. Conclusions Habitat selection patterns varied between individuals at different life stages and at different orders of selection. These analyses showed that denning packs and dispersal groups, the two pivotal life stages which drive wild dog population dynamics, exhibited different habitat selection to resident-non-breeding packs. Dispersal groups were relatively tolerant of higher human population densities whereas denning packs preferred rugged, remote areas. Evaluating different orders of selection was important as the above trends may not be detectable at all levels of selection for all habitat characteristics. Our analyses demonstrate that when life stage information is included in analyses across different orders of selection, it improves our understanding of how animals use their landscapes, thus providing important insights to aid conservation planning.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dalton C. Ludwick ◽  
Aaron C. Ericsson ◽  
Lisa N. Meihls ◽  
Michelle L. J. Gregory ◽  
Deborah L. Finke ◽  
...  

Abstract Western corn rootworm (Diabrotica virgifera virgifera LeConte) is a serious pest of maize (Zea mays L.) in North America and parts of Europe. With most of its life cycle spent in the soil feeding on maize root tissues, this insect is likely to encounter and interact with a wide range of soil and rhizosphere microbes. Our knowledge of the role of microbes in pest management and plant health remains woefully incomplete, yet that knowledge could play an important role in effective pest management strategies. For this study, insects were reared on maize in soils from different locations. Insects from two different laboratory colonies (a diapausing and a non-diapausing colony) were sampled at each life stage to determine the possible core bacteriome. Additionally, soil was sampled at each life stage and resulting bacteria were identified to determine the possible contribution of soil to the rootworm bacteriome, if any. We analyzed the V4 hypervariable region of bacterial 16S rRNA genes with Illumina MiSeq to survey the different species of bacteria associated with the insects and the soils. The bacterial community associated with insects was significantly different from that in the soil. Some differences appear to exist between insects from non-diapausing and diapausing colonies while no significant differences in community composition existed between the insects reared on different soils. Despite differences in the bacteria present in immature stages and in male and female adults, there is a possible core bacteriome of approximately 16 operational taxonomic units (i.e., present across all life stages). This research may provide insights into Bt resistance development, improved nutrition in artificial rearing systems, and new management strategies.


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