scholarly journals Interactions across life stages and thermal tolerance plasticity in Tigriopus californicus

2019 ◽  
Author(s):  
Timothy M. Healy ◽  
Antonia K. Bock ◽  
Ronald S. Burton
Keyword(s):  
Heat Shock ◽  
Thermal Tolerance ◽  
Life Stage ◽  
Interactive Effect ◽  
Atp Synthesis ◽  
Interactive Effects ◽  
Synthesis Rate ◽  
Life Stages ◽  
Tigriopus Californicus ◽  
Upper Thermal Tolerance

AbstractIn response to rapid environmental change, organisms rely on both genetic adaptation and phenotypic plasticity to adjust key traits that are necessary for survival and reproduction. Given the accelerating rate of climate change, plasticity may be particularly important. For organisms in warming aquatic habitats, upper thermal tolerance is likely to be a key trait, and many organisms express plasticity in this trait in response to developmental or adulthood temperatures. Although plasticity at one life stage may influence plasticity at another life stage, relatively little is known about these interactive effects for thermal tolerance. Here we used locally adapted populations of the intertidal copepod Tigriopus californicus to investigate these interactions in a marine ectotherm. We found that low latitude populations had greater critical thermal maxima (CTmax) than high latitude populations, and variation in developmental temperature altered CTmax plasticity in adulthood. After development at 25°C, CTmax was plastic in adults, whereas no adult plasticity in this trait was observed after 20°C development. This pattern was identical across four populations, suggesting that local thermal adaptation has not shaped this interactive effect. However, differences in the capacities to maintain ATP synthesis rates and to induce heat shock proteins at high temperatures, two likely mechanisms of local adaptation in this species, were consistent with changes in CTmax due to developmental temperatures, suggesting there is mechanistic overlap between plastic interactions and adaptation in general. These results indicate that interactive effects of plasticity across life stages may have substantial impacts on upper thermal tolerance in ectothermic organisms.Summary statementDevelopmental temperatures alter the plasticity of thermal limits in adults of a marine ectotherm, and differences in ATP synthesis rate and heat shock protein expression parallel the changes in tolerance.

scholarly journals Unshelled abalone and corrupted urchins: development of marine calcifiers in a changing ocean

2010 ◽  
Vol 278 (1716) ◽  
pp. 2376-2383 ◽  
Author(s):  
Maria Byrne ◽  
Melanie Ho ◽  
Eunice Wong ◽  
Natalie A. Soars ◽  
Paulina Selvakumaraswamy ◽  
...  
Keyword(s):  
Climate Change ◽  
Thermal Tolerance ◽  
Interactive Effect ◽  
Marine Species ◽  
Low Ph ◽  
Interactive Effects ◽  
Future Climate Change ◽  
Negative Effects ◽  
Negative Effect ◽  
Near Future

The most fragile skeletons produced by benthic marine calcifiers are those that larvae and juveniles make to support their bodies. Ocean warming, acidification, decreased carbonate saturation and their interactive effects are likely to impair skeletogenesis. Failure to produce skeleton in a changing ocean has negative implications for a diversity of marine species. We examined the interactive effects of warming and acidification on an abalone ( Haliotis coccoradiata ) and a sea urchin ( Heliocidaris erythrogramma ) reared from fertilization in temperature and pH/ p CO 2 treatments in a climatically and regionally relevant setting. Exposure of ectodermal (abalone) and mesodermal (echinoid) calcifying systems to warming (+2°C to 4°C) and acidification (pH 7.6–7.8) resulted in unshelled larvae and abnormal juveniles. Haliotis development was most sensitive with no interaction between stressors. For Heliocidaris , the percentage of normal juveniles decreased in response to both stressors, although a +2°C warming diminished the negative effect of low pH. The number of spines produced decreased with increasing acidification/ p CO 2 , and the interactive effect between stressors indicated that a +2°C warming reduced the negative effects of low pH. At +4°C, the developmental thermal tolerance was breached. Our results show that projected near-future climate change will have deleterious effects on development with differences in vulnerability in the two species.

scholarly journals Heat tolerance and thermal preference of the copepod Tigriopus californicus are insensitive to ecologically relevant dissolved oxygen levels

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Khuong V. Dinh ◽  
Arani Y. Cuevas-Sanchez ◽  
Katherine S. Buhl ◽  
Elizabeth A. Moeser ◽  
W. Wesley Dowd
Keyword(s):  
High Temperature ◽  
Dissolved Oxygen ◽  
Thermal Tolerance ◽  
Multiple Stressors ◽  
Interactive Effects ◽  
Egg Mass ◽  
Tigriopus Californicus ◽  
Oxygen Levels ◽  
Behavioral Preference ◽  
Diel Fluctuations

Abstract Shifting climate patterns may impose novel combinations of abiotic conditions on animals, yet understanding of the present-day interactive effects of multiple stressors remains under-developed. We tested the oxygen and capacity limited thermal tolerance (OCLTT) hypothesis and quantified environmental preference of the copepod Tigriopus californicus, which inhabits rocky-shore splashpools where diel fluctuations of temperature and dissolved oxygen (DO) are substantial. Egg-mass bearing females were exposed to a 5 h heat ramp to peak temperatures of 34.1–38.0 °C crossed with each of four oxygen levels: 22, 30, 100 and 250% saturation (4.7–5.3, 5.3–6.4, 21.2–21.3, and 50.7–53.3 kPa). Survival decreased at higher temperatures but was independent of DO. The behavioral preference of females was quantified in seven combinations of gradients of both temperature (11–37 °C) and oxygen saturation (17–206% or 3.6–43.6 kPa). Females avoided high temperatures regardless of DO levels. This pattern was more pronounced when low DO coincided with high temperature. In uniform temperature treatments, the distribution shifted toward high DO levels, especially in uniform high temperature, confirming that Tigriopus can sense environmental pO2. These results question the ecological relevance of OCLTT for Tigriopus and raise the possibility of microhabitat selection being used within splashpool environments to avoid physiologically stressful combinations of conditions.

scholarly journals Disparate patterns of thermal adaptation between life stages in temperate vs. tropical Drosophila melanogaster

2017 ◽  
Author(s):  
Brent L. Lockwood ◽  
Tarun Gupta ◽  
Rosemary Scavotto
Keyword(s):  
Climate Change ◽  
Drosophila Melanogaster ◽  
Heat Tolerance ◽  
Thermal Tolerance ◽  
Life Stage ◽  
Thermal Adaptation ◽  
Life Stages ◽  
Thermal Limits ◽  
Heat Tolerant ◽  
Selection For

AbstractMany terrestrial ectothermic species exhibit limited variation in upper thermal tolerance across latitude. However, these trends may not signify limited adaptive capacity to increase thermal tolerance in the face of climate change. Instead, thermal tolerance may be similar among populations because behavioral thermoregulation by mobile organisms or life stages may buffer natural selection for thermal tolerance. We compared thermal tolerance of adults and embryos among natural populations of Drosophila melanogaster from a broad range of thermal habitats around the globe to assess natural variation of thermal tolerance in mobile vs. immobile life stages. We found no variation among populations in adult thermal tolerance, but embryonic thermal tolerance was higher in tropical strains than in temperate strains. Average maximum temperature of the warmest month of the year predicted embryonic thermal tolerance in tropical but not temperate sites. We further report that embryos live closer to their upper thermal limits than adultso—i.e., thermal safety margins are smaller for embryos than adults. F1 hybrid embryos from crosses between temperate and tropical populations had thermal tolerance that matched that of tropical embryos, suggesting dominance of heat-tolerant alleles. Together our findings suggest that thermal selection has led to divergence in embryonic thermal tolerance but that selection for divergent thermal tolerance may be limited in adults. Further, our results suggest that thermal traits should be measured across life stages in order to better predict adaptive limits.Impact SummaryClimate change may threaten the extinction of many ectothermic species, unless populations can evolutionarily adapt to rising temperatures. Natural selection should favor individuals with higher heat tolerances in hotter environments. But recent studies have found that individuals from hot and cold places often have similar heat tolerances. This pattern may indicate that the evolution of heat tolerance is constrained. If this were true, then it would have dire consequences for species persistence under novel thermal conditions.An alternative explanation for lack of variation in heat tolerance is that mobile organisms don’t need higher heat tolerances to survive in hotter places. The majority of studies have focused on heat tolerance of the adult life stage. Yet, adults in many species are mobile organisms that can avoid extreme heat by seeking shelter in cooler microhabitats (e.g., shaded locations). In contrast, immobile life stages (e.g., insect eggs) cannot behaviorally avoid extreme heat. Thus, mobile and immobile life stages may face different thermal selection pressures that lead to disparate patterns of thermal adaptation across life stages.Here, we compared heat tolerances of fruit fly adults and eggs (Drosophila melanogaster) from populations in temperate North America and tropical locations around the globe. Consistent with previous studies, we found no differences among populations in adult heat tolerance. However, eggs from tropical flies were consistently more heat tolerant than eggs from North American flies. Further, eggs had lower heat tolerance than adults. Consequently, fly eggs in the hotter tropics may experience heat death more frequently than adult flies later in life. This may explain why patterns of divergence in heat tolerance were decoupled across life stages. These patterns indicate that thermal adaptation may be life-stage-specific and suggest that future work should characterize thermal traits across life stages to better understand the evolution of thermal limits.

Interactive toxic effects of agrochemicals on aquatic organisms

1999 ◽  
Vol 40 (1) ◽  
pp. 357-364 ◽  
Author(s):  
A. Kungolos ◽  
P. Samaras ◽  
A. M. Kipopoulou ◽  
A. Zoumboulis ◽  
G. P. Sakellaropoulos
Keyword(s):  
Daphnia Magna ◽  
Marine Bacterium ◽  
Methyl Parathion ◽  
Vibrio Fischeri ◽  
Interactive Effect ◽  
Algal Growth ◽  
Aquatic Organisms ◽  
Interactive Effects ◽  
Selenastrum Capricornutum ◽  
Toxic Compound

The effects of three common agrochemicals, lindane, methyl parathion and atrazine, on crustacean Daphnia magna, alga Selenastrum capricornutum and marine bacterium Vibrio fischeri were investigated in this study. Methyl parathion was the most toxic compound towards all three organisms, while lindane was more toxic to Daphnia magna and Vibrio fischeri than atrazine, and atrazine was more toxic to Selenastrum capricornutum than lindane. Among the three aquatic organisms, Selenastrum capricornutum was most sensitive in detecting lindane and atrazine toxicity, while Daphnia magna was most sensitive in detecting methyl parathion toxicity. The interactive effects of the pesticides were also investigated. The interactive effect between lindane and methyl parathion on survival of Daphnia magna was synergistic, while the ones between lindane and atrazine and between methyl parathion and atrazine were generally additive. The interactive effect of the three pesticides applied together on Daphnia magna was synergistic. The interactive effect of the three pesticides on the growth of Selenastrum capricornutum was antagonistic with few cases of addition, while the effect of all the three pairs of pesticides on algal growth was also antagonistic. The interactive effect of lindane and methyl parathion on Vibrio fischeri was additive.

‘And all my children?’

2018 ◽  
Author(s):  
Charlotte Scott
Keyword(s):  
Early Modern ◽  
Life Stage ◽  
Early Modern Period ◽  
Life Stages ◽  
Cultural Imagination ◽  
Modern Period

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.

Categorization flexibility and unconventional choices: is life an adventure?

2020 ◽  
Vol 54 (8) ◽  
pp. 1963-1986
Author(s):  
Tilottama G. Chowdhury ◽  
Feisal Murshed
Keyword(s):  
Interactive Effect ◽  
Interactive Effects ◽  
Cognitive Capacity ◽  
Purchase Behavior ◽  
Consumer Decision Making ◽  
Cross Sectional ◽  
Content Type ◽  
Cross Domain ◽  
Multiple Domains

Purpose This paper proposes that categorization flexibility, operationalized as the cognitive capacity that cross-categorizes products in multiple situational categories across multiple domains, might favorably influence a consumer’s evaluation of unconventional options. Design/methodology/approach Experimental research design is used to test the theory. An exploratory study first establishes the effect of categorization flexibility in a non-food domain. Study 1 documents the moderating role of decision domain, showing that the effect works only under low- (vs high-) consequence domain. Studies 2A and 2B further refine the notion by showing that individuals can be primed in a relatively higher categorization flexibility frame of mind. Study 3 demonstrates the interactive effect of categorization flexibility and adventure priming in a high-consequence domain. Study 4 integrates the interactive effects of decisions with low- vs high-consequence, adventure priming and categorization flexibility within a single decision domain of high consequence. Findings Consumers with higher- (vs lower-) categorization flexibility tend to opt for unconventional choices when the decision domain entails low consequences, whereas such a result does not hold under decision domain of high consequences. The categorization flexibility effects in case of low-consequence decision domain holds true even when consumers are primed to be categorization flexible. Furthermore, with additional adventure priming, consumers show an increased preference for unconventional options even under a decision domain with high consequence. Research limitations/implications This study could not examine real purchase behavior as results are based on cross-sectional, behavioral intention data. In addition, it did not examine the underlying reason for presence of cross-domain categorization flexibility index. Practical implications The results suggest that stimuli may be tailored to consumers in ways that increase the salience and the perceived attractiveness of unconventional choices. Further, data reinforce the notion of cross-categorical interrelations among different domains, which could be leveraged by marketers. Originality/value This study represents the first documentation of the potential ways by which unconventional product choice might be a function of individuals’ categorization flexibility level across different types of decision domains. The findings yield implications that are novel to both categorization and consumer decision-making literature.

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