1
|
Haskett H, Gill L, Spicer JI, Truebano M. The embryonic thermal environment has positive but weak effects on thermal tolerance later in life in the aquatic invertebrate Gammarus chevreuxi. Mar Environ Res 2024; 195:106350. [PMID: 38219380 DOI: 10.1016/j.marenvres.2024.106350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/16/2024]
Abstract
Recent evidence suggests that the adult phenotype is influenced by temperatures experienced in early life. However, our understanding of the extent to which the embryonic environment can modulate thermal tolerance later in life is limited, owing to the paucity of studies with appropriate experimental designs to test for this form of developmental plasticity. We investigated whether the thermal environment experienced during embryonic development affects thermal limits in later life. Embryos of the estuarine amphipod Gammarus chevreuxi were incubated until hatching to 15 °C, 20 °C and 25 °C, then reared under a common temperature. Using thermal ramping assays, we determined upper thermal limits in juveniles, four weeks post-hatch. Individuals exposed to higher temperatures during embryonic development displayed greater thermal tolerance as juveniles (acclimation response ratio ≈ 0.10-0.25 for upper lethal temperature). However, we suggest that the degree of developmental plasticity observed is limited, and will provide little benefit under future climate change scenarios.
Collapse
Affiliation(s)
- Honor Haskett
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Plymouth, Drake Circus, Plymouth, PL4 8AA, UK
| | - Luke Gill
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Plymouth, Drake Circus, Plymouth, PL4 8AA, UK
| | - John I Spicer
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Plymouth, Drake Circus, Plymouth, PL4 8AA, UK
| | - Manuela Truebano
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
| |
Collapse
|
2
|
Weber TA, Dichiera AM, Brauner CJ. Resetting thermal limits: 10-year-old white sturgeon display pronounced but reversible thermal plasticity. J Therm Biol 2024; 119:103807. [PMID: 38340465 DOI: 10.1016/j.jtherbio.2024.103807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024]
Abstract
While many ectotherms improve thermal tolerance in response to prolonged thermal stress, little is known about the lasting effects of warm acclimation after returning to cooler temperatures. Furthermore, thermal stress may disproportionately impact threatened and endangered species. To address this, we repeatedly measured critical thermal maxima (CTmax; °C) and associated stress responses (hematocrit, hemoglobin concentration, plasma cortisol) of endangered subadult white sturgeon (Acipenser transmontanus) in response to control temperature (pre-acclimation; 14°C), after 1 month at either control or warm temperature (acclimation; 14°C or 20°C), and after one smonth following return to control temperature (post-acclimation; 14°C). While control fish demonstrated fairly repeatable thermal tolerance (interclass correlation coefficient = 0.479), warm-acclimated fish experienced a ∼3.1°C increase in thermal tolerance and when re-acclimated to control temperature, decreased thermal tolerance ∼1.9°C. Hematocrit, hemoglobin concentration, and final splenic somatic index (spleen mass relative to whole body mass, collected after post-acclimation CTmax) were not significantly different between control and treatment fish, suggesting no effects of warm acclimation on aerobic capacity. Plasma cortisol was significantly higher in control fish after pre-acclimation and post-acclimation CTmax trials, but importantly, acclimation temperature did not affect this response. Strikingly, final hepatosomatic index (relative liver size) was 45% lower in treatment fish, indicating warm acclimation may have lasting effects on energy usage and metabolism, even after reacclimating to control temperature. To our knowledge, these 10-year-old subadult sturgeon are the oldest sturgeon experimentally tested with regards to thermal plasticity and demonstrate incredible capacity for thermal acclimation relative to other fishes. However, more research is needed to determine whether the ability to acclimate to warm temperature may come with a persistent cost.
Collapse
Affiliation(s)
- Theresa A Weber
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Angelina M Dichiera
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada; Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia, USA.
| | - Colin J Brauner
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
3
|
Sasaki M, Woods C, Dam HG. Parasitism does not reduce thermal limits in the intermediate host of a bopyrid isopod. J Therm Biol 2023; 117:103712. [PMID: 37714113 DOI: 10.1016/j.jtherbio.2023.103712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/17/2023]
Abstract
Parasitism has strong effects on community dynamics. Given the detrimental effects parasites have on host health, infection or infestation might be expected to reduce upper thermal limits, increasing the vulnerability of host species to future climate change. Copepods are integral components of aquatic food webs and biogeochemical cycles. They also serve as intermediate hosts in the life cycle of parasitic isopods in the family Bopyridae. As both copepods and isopod parasites play important roles in aquatic communities, it is important to understand how the interaction between parasite and host affects thermal limits in order to better predict how community dynamics may change in a warming climate. Here we examined the effect of infestation by larvae of a bopyrid isopod on the cosmopolitan copepod Acartia tonsa to test the hypothesis that infestation reduces thermal limits. To aid with this work, we developed an affordable, highly portable system for measuring critical thermal maxima of small ectotherms. We also used meta-analysis to summarize the effects of parasitism on critical thermal maxima in a wider range of taxa to help contextualize our findings. Contrary to both our hypothesis and the results of previous studies, we observed no reduction of thermal limits by parasitism in A. tonsa. These results suggest that life history of the host and parasite may interact to determine how parasite infestation affects environmental sensitivity.
Collapse
Affiliation(s)
- Matthew Sasaki
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA; Department of Biology, University of Vermont, Burlington, VT, 05401, USA.
| | - Charles Woods
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA
| | - Hans G Dam
- Department of Marine Sciences, University of Connecticut, Groton, CT, 06340, USA
| |
Collapse
|
4
|
Penman RJ, Bugg W, Rost-Komiya B, Earhart ML, Brauner CJ. Slow heating rates increase thermal tolerance and alter mRNA HSP expression in juvenile white sturgeon (Acipenser transmontanus). J Therm Biol 2023; 115:103599. [PMID: 37413754 DOI: 10.1016/j.jtherbio.2023.103599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/13/2023] [Accepted: 05/14/2023] [Indexed: 07/08/2023]
Abstract
Freshwater fish such as white sturgeon (Acipenser transmontanus) are particularly vulnerable to the effects of anthropogenically induced global warming. Critical thermal maximum tests (CTmax) are often conducted to provide insight into the impacts of changing temperatures; however, little is known about how the rate of temperature increase in these assays affects thermal tolerance. To assess the effect of heating rate (0.3 °C/min, 0.03 °C/min, 0.003 °C/min) we measured thermal tolerance, somatic indices, and gill Hsp mRNA expression. Contrary to what has been observed in most other fish species, white sturgeon thermal tolerance was highest at the slowest heating rate of 0.003 °C/min (34.2 °C, and CTmax of 31.3 and 29.2 °C, for rates 0.03 and 0.3 °C/min, respectively) suggesting an ability to rapidly acclimate to slowly increasing temperatures. Hepatosomatic index decreased in all heating rates relative to control fish, indicative of the metabolic costs of thermal stress. At the transcriptional level, slower heating rates resulted in higher gill mRNA expression of Hsp90a, Hsp90b, and Hsp70. Hsp70 mRNA expression was increased in all heating rates relative to controls, whereas expression of Hsp90a and Hsp90b mRNA only increased in the two slower trials. Together these data indicate that white sturgeon have a very plastic thermal response, which is likely energetically costly to induce. Acute temperature changes may be more detrimental to sturgeon as they struggle to acclimate to rapid changes in their environment, however under slower warming rates they demonstrate strong thermal plasticity to warming.
Collapse
Affiliation(s)
- Rachael J Penman
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada.
| | - William Bugg
- Department of Biology, The University of Manitoba, Winnipeg, Manitoba, Canada
| | - Beatrice Rost-Komiya
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Madison L Earhart
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin J Brauner
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
5
|
Dallas JW, Warne RW. Ranavirus infection does not reduce heat tolerance in a larval amphibian. J Therm Biol 2023; 114:103584. [PMID: 37209633 DOI: 10.1016/j.jtherbio.2023.103584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/22/2023]
Abstract
Extreme heat events and emerging infectious diseases negatively impact wildlife populations, but the interacting effects of infection and host heat tolerance remain understudied. The few studies covering this subject have demonstrated that pathogens lower the heat tolerance of their hosts, which places infected hosts at a greater risk experiencing lethal heat stress. Here, we studied how ranavirus infection influenced heat tolerance in larval wood frogs (Lithobates sylvaticus). In line with similar studies, we predicted the elevated costs of ranavirus infection would lower heat tolerance, measured as critical thermal maximum (CTmax), compared to uninfected controls. Ranavirus infection did not reduce CTmax and there was a positive relationship between CTmax and viral loads. Our results demonstrate that ranavirus-infected wood frog larvae had no loss in heat tolerance compared to uninfected larvae, even at viral loads associated with high mortality rates, which contradicts the common pattern for other pathogenic infections in ectotherms. Larval anurans may prioritize maintenance of their CTmax when infected with ranavirus to promote selection of warmer temperatures during behavioral fever that can improve pathogen clearance. Our study represents the first to examine the effect of ranavirus infection on host heat tolerance, and because no decline in CTmax was observed, this suggests that infected hosts would not be under greater risk of heat stress.
Collapse
Affiliation(s)
- Jason W Dallas
- School of Biological Sciences, Southern Illinois University Carbondale, 1125 Lincoln Street, Carbondale, IL, 62901, USA.
| | - Robin W Warne
- School of Biological Sciences, Southern Illinois University Carbondale, 1125 Lincoln Street, Carbondale, IL, 62901, USA
| |
Collapse
|
6
|
Turriago JL, Tejedo M, Hoyos JM, Camacho A, Bernal MH. The time course of acclimation of critical thermal maxima is modulated by the magnitude of temperature change and thermal daily fluctuations. J Therm Biol 2023; 114:103545. [PMID: 37290261 DOI: 10.1016/j.jtherbio.2023.103545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/09/2023] [Accepted: 03/12/2023] [Indexed: 06/10/2023]
Abstract
Plasticity in the critical thermal maximum (CTmax) helps ectotherms survive in variable thermal conditions. Yet, little is known about the environmental mechanisms modulating its time course. We used the larvae of three neotropical anurans (Boana platanera, Engystomops pustulosus and Rhinella horribilis) to test whether the magnitude of temperature changes and the existence of fluctuations in the thermal environment affected both the amount of change in CTmax and its acclimation rate (i.e., its time course). For that, we transferred tadpoles from a pre-treatment temperature (23 °C, constant) to two different water temperatures: mean (28 °C) and hot (33 °C), crossed with constant and daily fluctuating thermal regimes, and recorded CTmax values, daily during six days. We modeled changes in CTmax as an asymptotic function of time, temperature, and the daily thermal fluctuation. The fitted function provided the asymptotic CTmax value (CTmax∞) and CTmax acclimation rate (k). Tadpoles achieved their CTmax∞ between one and three days. Transferring tadpoles to the hot treatment generated higher CTmax∞ at earlier times, inducing faster acclimation rates in tadpoles. In contrast, thermal fluctuations equally led to higher CTmax∞ values but tadpoles required longer times to achieve CTmax∞ (i.e., slower acclimation rates). These thermal treatments interacted differently with the studied species. In general, the thermal generalist Rhinella horribilis showed the most plastic acclimation rates whereas the ephemeral-pond breeder Engystomops pustulosus, more exposed to heat peaks during larval development, showed less plastic (i.e., canalized) acclimation rates. Further comparative studies of the time course of CTmax acclimation should help to disentangle the complex interplay between the thermal environment and species ecology, to understand how tadpoles acclimate to heat stress.
Collapse
Affiliation(s)
- Jorge L Turriago
- Grupo de Herpetología, Eco-Fisiología & Etología, Department of Biology, Universidad del Tolima, Tolima, 730006299, Colombia; Programa Doctorado en Ciencias Biológicas, Pontificia Universidad Javeriana, Bogotá, 11001000, Colombia.
| | - Miguel Tejedo
- Department of Evolutionary Ecology, Estación Biológica de Doñana, CSIC, Sevilla, 41092, Spain.
| | - Julio M Hoyos
- Grupo UNESIS, Department of Biology, Pontificia Universidad Javeriana, Bogotá, 11001000, Colombia.
| | - Agustín Camacho
- Department of Evolutionary Ecology, Estación Biológica de Doñana, CSIC, Sevilla, 41092, Spain.
| | - Manuel H Bernal
- Grupo de Herpetología, Eco-Fisiología & Etología, Department of Biology, Universidad del Tolima, Tolima, 730006299, Colombia.
| |
Collapse
|
7
|
Weber AV, Firth BL, Cadonic IG, Craig PM. Interactive effects of venlafaxine and thermal stress on zebrafish (Danio rerio) inflammatory and heat shock responses. Comp Biochem Physiol C Toxicol Pharmacol 2023; 269:109620. [PMID: 37004898 DOI: 10.1016/j.cbpc.2023.109620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/18/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023]
Abstract
Venlafaxine (VFX), a commonly prescribed antidepressant often detected in wastewater effluent, and acute temperature elevations from climate change and increased urbanization, are two environmental stressors currently placing freshwater ecosystems at risk. This study focused on understanding if exposure to VFX impacts the agitation temperature (Tag) and critical thermal maximum (CTmax) of zebrafish (Danio rerio). Additionally, we examined the interactive effects of VFX and acute thermal stress on zebrafish heat shock and inflammatory immune responses. A 96 h 1.0 μg/L VFX exposure experiment was conducted, followed by assessment of thermal tolerance via CTmax challenge. Heat shock proteins and pro-inflammatory immune cytokines were quantified through gene expression analysis by quantitative PCR (qPCR) on hsp 70, hsp 90, hsp 47, il-8, tnfα, and il-1β within gill and liver tissue. No significant changes in agitation temperature between control and exposed fish were observed, nor were there any differences in CTmax based on treatment. Unsurprisingly, hsp 47, 70, and 90 were all upregulated in groups exposed solely to CTmax, while only hsp 47 within gill tissue showed signs of interactive effects, which was significantly decreased in fish exposed to both VFX and CTmax. No induction of an inflammatory response occurred. This study demonstrated that environmentally relevant concentrations of VFX have no impact on thermal tolerance performance in zebrafish. However, VFX can cause diminished function of protective heat shock mechanisms, which could be detrimental to freshwater fish populations and aquatic ecosystems as temperature spikes become more frequent from climate change and urbanization near watersheds.
Collapse
Affiliation(s)
- A V Weber
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - B L Firth
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada. https://twitter.com/@Britney_Firth
| | - I G Cadonic
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada. https://twitter.com/@IvanCadonic
| | - P M Craig
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
| |
Collapse
|
8
|
Baag S, Mandal S. Do predator (Mystus gulio) and prey (Penaeus monodon) have differential response against heatwaves? Unveiling through oxidative stress biomarkers and thermal tolerance estimation. Mar Environ Res 2023; 184:105850. [PMID: 36566576 DOI: 10.1016/j.marenvres.2022.105850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
Extreme climatic events such as heatwaves are anticipated to intensify in future and impose additional thermal stress to aquatic animals. Knowledge regarding an organism's thermal tolerance or sensitivity is therefore important in determining the effects of fluctuating water temperature on physiological responses. Thus, thermal tolerance tests can serve as a first step in understanding the present and future effects of climate warming. Climatic variability will alter prey-predator attributes differentially and impact their subsequent interactions. The key objective of this study was to compare and decode the stress responses, resistance and vulnerability of two economically important species from Sundarbans estuarine system- Penaeus monodon (prey) and Mystus gulio (predator) subjected to acute thermal challenges such as sudden heatwaves. Both the species were subjected to an increasing thermal ramp of 1°C h-1 from 22°C to 42°C. Organisms were observed continuously throughout the ramping period and changes in the locomotory behaviour were followed until their loss of equilibrium. The digestive tissue samples were dissected out from both M. gulio and P. monodon at every 2°C and also after a recovery period of 48 h. The SOD, CAT, GST, LPO were measured and integrated biomarker response (IBR) was analysed. The results from thermal tolerance maxima estimation, biomarker study, IBR responses indicated more intense stress response in fish M. gulio whereas recovery potential was greater in shrimp P. monodon. Our findings corroborate the 'trophic sensitivity hypothesis' which advocates predators to be less tolerant in aggravated environmental stress than their prey.
Collapse
Affiliation(s)
- Sritama Baag
- Marine Ecology Laboratory, Department of Life Sciences, Presidency University, 86/1, College Street, Kolkata, 700073, India
| | - Sumit Mandal
- Marine Ecology Laboratory, Department of Life Sciences, Presidency University, 86/1, College Street, Kolkata, 700073, India.
| |
Collapse
|
9
|
Muluvhahothe MM, Joubert E, Foord SH. Thermal tolerance responses of the two-spotted stink bug, Bathycoelia distincta (Hemiptera: Pentatomidae), vary with life stage and the sex of adults. J Therm Biol 2023; 111:103395. [PMID: 36585076 DOI: 10.1016/j.jtherbio.2022.103395] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/22/2022] [Accepted: 11/22/2022] [Indexed: 12/09/2022]
Abstract
Temperature tolerance is an essential component of insect fitness, and its understanding can provide a predictive framework for their distribution and abundance. The two-spotted stink bug, Bathycoelia distincta Distant, is a significant pest of macadamia. The main goal of this study was to investigate the thermal tolerance of B. distincta across different life stages. Thermal tolerance indices investigated included critical thermal maximum (CTmax), critical thermal minimum (CTmin), effects of acclimation on CTmax and CTmin at 20, 25, and 30 °C, and rapid heat hardening (RHH), and rapid cold hardening (RCH). The Kruskal-Wallis test was used to explore the effects of life stage and acclimation on CTmax and CTmin and Generalized Linear Models (GLM) for the probability of survival after pre-exposure to RHH at 41 °C for 2 h and RCH at -8 °C for 2 h. CTmax and CTmin varied significantly between life stages at all acclimation temperatures, but CTmin (3.5 °C) varied more than CTmax (2.1 °C). Higher acclimation temperatures resulted in larger variations between life stages for both CTmax and CTmin. A significant acclimation response was observed for the CTmax of instar 2 (1.7 °C) and CTmin of females (2.7 °C) across acclimation temperatures (20-30 °C). Pre-exposure significantly improved the heat and cold survival probability of instar 2 and the cold survival probability of instar 3 and males. The response between life stages was more variable in RCH than in RHH. Instar 2 appeared to be the most thermally plastic life stage of B. distincta. These results suggest that the thermal plastic traits of B. distincta life stages may enable this pest to survive in temperature regimes under the ongoing climate change, with early life stages (except for instar 2) more temperature sensitive than later life stages.
Collapse
Affiliation(s)
- Mulalo M Muluvhahothe
- SARChI-Chair on Biodiversity Value and Change, Department of Biological Sciences, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou, 0950, South Africa.
| | - Elsje Joubert
- Levubu Centre for Excellence, PO Box 121, Levubu, 0929, South Africa
| | - Stefan H Foord
- SARChI-Chair on Biodiversity Value and Change, Department of Biological Sciences, Faculty of Science, Engineering and Agriculture, University of Venda, Private Bag X5050, Thohoyandou, 0950, South Africa
| |
Collapse
|
10
|
Kuyucu AC, Chown SL. Time course of acclimation of critical thermal limits in two springtail species (Collembola). J Insect Physiol 2021; 130:104209. [PMID: 33609519 DOI: 10.1016/j.jinsphys.2021.104209] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 01/12/2021] [Accepted: 02/11/2021] [Indexed: 06/12/2023]
Abstract
Critical thermal limits are one of the most important sources of information on the possible impacts of climate change on soil microarthropods. The extent of plasticity of tolerance limits can provide valuable insights about the likely responses of ectotherms to environmental change. Although many studies have investigated various aspects of the acclimatory response of thermal limits to temperature changes in arthropods, the number of studies focusing on the temporal dynamics of this plastic response is relatively small. Collembola, one of the key microarthropods groups in almost all soil ecosystems around the world, have been the focus of several thermal acclimation studies. Yet the time course of acclimation and its reversal have not been widely studied in this group. Here we investigated the time course of acclimation of critical thermal maxima (CTmax) and minima (CTmin) of two springtail species. We exposed a Cryptopygus species from temperate southern Australia to high and low temperature conditions and Mucrosomia caeca from Sub-Antarctic Macquarie Island to high temperature conditions. Upper thermal limits in both species were found to be highly constrained, as CTmax did not show substantial response to high and low temperature acclimation both in the Cryptopygus species and M. caeca, whereas CTmin showed significant responses to high and low temperature conditions. The acclimation begins to stabilize in approximately seven days in all treatments except for the acclimation of CTmin under high temperature conditions, where the pattern of change suggests that this acclimation might take longer to be completed. Although reversal of this acclimation also begins to stabilize under 7 days, re-acclimation was relatively slow as we did not observe a very clear settling point in 2 of the 3 re-acclimation treatments. The observed limits on the plasticity of CTmax indicate that both of these species may be very limited in their ability to respond plastically to short-term rapid changes in temperature (i.e temperature extremes).
Collapse
Affiliation(s)
- Arda C Kuyucu
- Hacettepe University, Department of Biology, Ankara 06800, Turkey.
| | - Steven L Chown
- School of Biological Sciences, Monash University, Victoria 3800, Australia
| |
Collapse
|
11
|
Hirakawa KA, Salinas S. Short communication: Domesticated and wild fathead minnows differ in growth and thermal tolerance. J Therm Biol 2020; 94:102784. [PMID: 33292977 DOI: 10.1016/j.jtherbio.2020.102784] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 10/09/2020] [Accepted: 11/07/2020] [Indexed: 11/26/2022]
Abstract
Many populations have evolved in response to laboratory environments (lack of predators, continual food availability, etc.). Another potential agent of selection in the lab is exposure to constant thermal environments. Here, we examined changes in growth, critical thermal maximum (CTmax), and food consumption under constant (25 °C) and fluctuating (22-28 °C and 19-31 °C) conditions in two populations of fathead minnows, Pimephales promelas: one that has been kept in a laboratory setting for over 120 generations (~40 years) and a corresponding wild one. We found that under thermal fluctuations, domesticated fathead minnows grew faster than their wild counterparts, but also exhibited lower thermal tolerance. Food consumption was significantly higher in the lab population under the constant and large fluctuation thermal treatments. Our results suggest that the lab population has adjusted to the stable conditions in the laboratory and that we should carefully apply lessons learned in the lab to wild populations.
Collapse
Affiliation(s)
- Kento A Hirakawa
- Department of Biology, Kalamazoo College, 1200 Academy St., Kalamazoo, MI, 49006, USA
| | - Santiago Salinas
- Department of Biology, Kalamazoo College, 1200 Academy St., Kalamazoo, MI, 49006, USA.
| |
Collapse
|
12
|
Yilmaz AR, Chick LD, Perez A, Strickler SA, Vaughn S, Martin RA, Diamond SE. Remarkable insensitivity of acorn ant morphology to temperature decouples the evolution of physiological tolerance from body size under urban heat islands. J Therm Biol 2019; 85:102426. [PMID: 31657738 DOI: 10.1016/j.jtherbio.2019.102426] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 06/17/2019] [Accepted: 09/29/2019] [Indexed: 12/31/2022]
Abstract
Environmental temperature can alter body size and thermal tolerance, yet the effects of temperature rise on the size-tolerance relationship remain unclear. Terrestrial ectotherms with larger body sizes typically exhibit greater tolerance of high (and low) temperatures. However, while warming tends to increase tolerance of high temperatures through phenotypic plasticity and evolutionary change, warming tends to decrease body size through these mechanisms and thus might indirectly contribute to worse tolerance of high temperatures. These contrasting effects of warming on body size, thermal tolerance, and their relationship are increasingly important in light of global climate change. Here, we used replicated urban heat islands to explore the size-tolerance relationship in response to warming. We performed a common garden experiment with a small acorn-dwelling ant species collected from urban and rural populations across three different cities and reared under five laboratory rearing temperatures from 21 to 29 °C. We found that acorn ant body size was remarkably insensitive to laboratory rearing temperature (ant workers exhibited no phenotypic plasticity in body size across rearing temperature) and among populations experiencing cooler rural versus warmer urban environmental temperatures (no evolved differences in body size between urban and rural populations). Further, this insensitivity of body size to temperature was highly consistent across each of the three cities we examined. Because body size was robust to temperature variation, previously described plastic and evolved shifts in heat (and cold) tolerance in acorn ant responses to urbanization were shown to be independent of shifts in body size. Indeed, genetic (colony-level) correlations between heat and cold tolerance traits and body size revealed no significant association between size and tolerance. Our results show how typical trait correlations, such as between size and thermal tolerance, might be decoupled as populations respond to contemporary environmental change.
Collapse
Affiliation(s)
- Aaron R Yilmaz
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA.
| | - Lacy D Chick
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Abe Perez
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | | | - Selby Vaughn
- Hathaway Brown School, Shaker Heights, OH, 44122, USA
| | - Ryan A Martin
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Sarah E Diamond
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA
| |
Collapse
|
13
|
Tripp-Valdez MA, Bock C, Lannig G, Koschnick N, Pörtner HO, Lucassen M. Assessment of muscular energy metabolism and heat shock response of the green abalone Haliotis fulgens (Gastropoda: Philipi) at extreme temperatures combined with acute hypoxia and hypercapnia. Comp Biochem Physiol B Biochem Mol Biol 2018; 227:1-11. [PMID: 30195088 DOI: 10.1016/j.cbpb.2018.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/24/2018] [Accepted: 08/29/2018] [Indexed: 10/28/2022]
Abstract
The interaction between ocean warming, hypoxia and hypercapnia, suggested by climate projections, may push an organism earlier to the limits of its thermal tolerance window. In a previous study on juveniles of green abalone (Haliotis fulgens), combined exposure to hypoxia and hypercapnia during heat stress induced a lowered critical thermal maximum (CTmax), indicated by constrained oxygen consumption, muscular spams and loss of attachment. Thus, the present study investigated the cell physiology in foot muscle of H. fulgens juveniles exposed to acute warming (18 °C to 32 °C at +3 °C day-1) under hypoxia (50% air saturation) and hypercapnia (~1000 μatm PCO2), alone and in combination, to decipher the mechanisms leading to functional loss in this tissue. Under exposure to either hypoxia or hypercapnia, citrate synthase (CS) activity decreased with initial warming, in line with thermal compensation, but returned to control levels at 32 °C. The anaerobic enzymes lactate and tauropine dehydrogenase increased only under hypoxia at 32 °C. Under the combined treatment, CS overcame thermal compensation and remained stable overall, indicating active mitochondrial regulation under these conditions. Limited accumulation of anaerobic metabolites indicates unchanged mode of energy production. In all treatments, upregulation of Hsp70 mRNA was observed already at 30 °C. However, lack of evidence for Hsp70 protein accumulation provides only limited support to thermal denaturation of proteins. We conclude that under combined hypoxia and hypercapnia, metabolic depression allowed the H. fulgens musculature to retain an aerobic mode of metabolism in response to warming but may have contributed to functional loss.
Collapse
Affiliation(s)
- Miguel A Tripp-Valdez
- Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570 Bremerhaven, Germany.
| | - Christian Bock
- Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570 Bremerhaven, Germany
| | - Gisela Lannig
- Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570 Bremerhaven, Germany
| | - Nils Koschnick
- Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570 Bremerhaven, Germany
| | - Hans O Pörtner
- Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570 Bremerhaven, Germany; University Bremen, Bibliothekstraße 1, 28359, Germany
| | - Magnus Lucassen
- Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, D-27570 Bremerhaven, Germany
| |
Collapse
|
14
|
Christen F, Desrosiers V, Dupont-Cyr BA, Vandenberg GW, Le François NR, Tardif JC, Dufresne F, Lamarre SG, Blier PU. Thermal tolerance and thermal sensitivity of heart mitochondria: Mitochondrial integrity and ROS production. Free Radic Biol Med 2018; 116:11-18. [PMID: 29294390 DOI: 10.1016/j.freeradbiomed.2017.12.037] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/17/2017] [Accepted: 12/29/2017] [Indexed: 12/21/2022]
Abstract
Cardiac mitochondrial metabolism provides 90% of the ATP necessary for the contractile exertion of the heart muscle. Mitochondria are therefore assumed to play a pivotal role in heart failure (HF), cardiovascular disease and ageing. Heat stress increases energy metabolism and oxygen demand in tissues throughout the body and imposes a major challenge on the heart, which is suspected of being the first organ to fail during heat stress. The underlying mechanisms inducing heart failure are still unclear. To pinpoint the processes implicated in HF during heat stress, we measured mitochondrial respiration rates and hydrogen peroxide production of isolated Arctic char (Salvelinus alpinus) heart mitochondria at 4 temperatures: 10°C (acclimation), 15°C, 20°C and 25°C (just over critical maximum). We found that at temperature ranges causing the loss of an organism's general homeostasis (between 20°C and 25°C) and with a substrate combination close to physiological conditions, the heat-induced increase in mitochondrial oxygen consumption levels off. More importantly, at the same state, hydrogen peroxide efflux increased by almost 50%. In addition, we found that individuals with low mitochondrial respiration rates produced more hydrogen peroxide at 10°C, 15°C and 20°C. This could indicate that individuals with cardiac mitochondria having a low respiratory capacity, have a more fragile heart and will be more prone to oxidative stress and HF, and less tolerant to temperature changes and other stressors. Our results show that, at temperatures close to the thermal limit, mitochondrial capacity is compromised and ROS production rates increase. This could potentially alter the performance of the cardiac muscle and lead to heat-induced HF underlining the important role that mitochondria play in setting thermal tolerance limits.
Collapse
Affiliation(s)
- Felix Christen
- Université du Québec à Rimouski, Département de biologie, Rimouski, Québec, Canada G5L3A1
| | - Véronique Desrosiers
- Université du Québec à Rimouski, Département de biologie, Rimouski, Québec, Canada G5L3A1
| | - Bernard A Dupont-Cyr
- Université du Québec à Rimouski, Département de biologie, Rimouski, Québec, Canada G5L3A1
| | - Grant W Vandenberg
- Université Laval, Département de sciences animales, Québec, Canada G1V 0A6
| | | | - Jean-Claude Tardif
- Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada H1T 1C8
| | - France Dufresne
- Université du Québec à Rimouski, Département de biologie, Rimouski, Québec, Canada G5L3A1
| | - Simon G Lamarre
- Université de Moncton, Département de biologie, Moncton, New-Brunswick, Canada E1A 3E9
| | - Pierre U Blier
- Université du Québec à Rimouski, Département de biologie, Rimouski, Québec, Canada G5L3A1.
| |
Collapse
|
15
|
Bujan J, Kaspari M. Nutrition modifies critical thermal maximum of a dominant canopy ant. J Insect Physiol 2017; 102:1-6. [PMID: 28830761 DOI: 10.1016/j.jinsphys.2017.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 08/13/2017] [Accepted: 08/17/2017] [Indexed: 06/07/2023]
Abstract
While adaptive responses to climate gradients are increasingly documented, little is known about how individuals alter their upper thermal tolerances. Long-term increases in dietary carbohydrates can elevate upper thermal tolerances in insects. We explored how the nutritional state of a Neotropical canopy ant governs its CTmax - the temperature at which individuals lose muscle control. We predicted that Azteca chartifex workers recently fed a carbohydrate-rich diet, such as honeydew and extrafloral nectar, would use that energy to increase their CTmax. Moreover, if a carbohydrate-rich diet increases CTmax, then we predicted that ants from colonies with high CTmaxs feed at a lower trophic level, and thus have a higher carbon:nitrogen ratio. We used A. chartifex colonies from a long-term fertilization experiment where phosphorus addition increased A. chartifex foraging activity with respect to controls. As foraging activity can be governed by resource availability, we first measured CTmax of field collected colonies. In freshly collected field colonies, CTmax was 2°C higher in control plots. This difference disappeared when ants were provided with only water for 10h. Ants were then provided with a 10% sucrose solution ad lib which increased CTmax by 5°C. We thus support the hypothesis that enhanced carbohydrate nutrition enables higher thermal tolerance, but this does not appear to be linked to colony trophic status, higher carbon:nitrogen ratios, or higher total body phosphorus. This short-term thermal plasticity linked to carbohydrate nutrition demonstrates the importance of ant diet in shaping their physiological traits. It is especially relevant to ant species that maintain high abundance by feeding on plant exudates. In a rapidly warming world, carbohydrate availability and use may represent a new element for predicting population and community responses of herbivorous insects.
Collapse
Affiliation(s)
- Jelena Bujan
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK, USA.
| | - Michael Kaspari
- Department of Biology, Graduate Program in Ecology and Evolutionary Biology, University of Oklahoma, Norman, OK, USA; Smithsonian Tropical Research Institute, Balboa, Ancon, Panama
| |
Collapse
|
16
|
Oyen KJ, Giri S, Dillon ME. Altitudinal variation in bumble bee (Bombus) critical thermal limits. J Therm Biol 2016; 59:52-7. [PMID: 27264888 DOI: 10.1016/j.jtherbio.2016.04.015] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/29/2016] [Accepted: 04/30/2016] [Indexed: 10/21/2022]
Abstract
Organism critical thermal limits are often tightly linked to current geographic distribution and can therefore help predict future range shifts driven by changing environmental temperatures. Thermal tolerance of diverse organisms often varies predictably with latitude, with upper thermal limits changing little and lower thermal limits decreasing with latitude. Despite similarly steep gradients in environmental temperatures across altitude, few studies have investigated altitudinal variation in critical thermal limits. We estimated critical thermal minimum (CTmin), critical thermal maximum (CTmax) and recovery temperature (Trec) by tracking righting response of three bumble bee species during thermal ramps: Bombus huntii collected from 2180m asl, and Bombus bifarius and Bombus sylvicola collected from 3290m asl in Wyoming, USA. Overall, larger bees could tolerate more extreme temperatures, likely due to a thermal inertia driven lag between core body temperatures and air temperatures. Despite their smaller size, high altitude bumble bees tolerated colder air temperatures: they had ~1°C lower CTmin and recovered from cold exposure at ~3-4°C lower air temperatures. Conversely, low altitude bees tolerated ~5°C hotter air temperatures. These altitudinal differences in thermal tolerance parallel differences in average daily minimum (1.2°C) and maximum (7.5°C) temperatures between these sites. These results provide one of the few measurements of organism thermal tolerance across altitude and the first evidence for geographical differences in tolerance of temperature extremes in heterothermic bumble bees.
Collapse
Affiliation(s)
- K Jeannet Oyen
- Department of Zoology and Physiology & Program in Ecology, University of Wyoming, Laramie, WY 82071, USA.
| | - Susma Giri
- Department of Zoology and Physiology & Program in Ecology, University of Wyoming, Laramie, WY 82071, USA
| | - Michael E Dillon
- Department of Zoology and Physiology & Program in Ecology, University of Wyoming, Laramie, WY 82071, USA
| |
Collapse
|
17
|
DeVries ZC, Kells SA, Appel AG. Estimating the critical thermal maximum (CTmax) of bed bugs, Cimex lectularius: Comparing thermolimit respirometry with traditional visual methods. Comp Biochem Physiol A Mol Integr Physiol 2016; 197:52-7. [PMID: 26970580 DOI: 10.1016/j.cbpa.2016.03.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 03/02/2016] [Accepted: 03/03/2016] [Indexed: 10/22/2022]
Abstract
Evaluating the critical thermal maximum (CTmax) in insects has provided a number of challenges. Visual observations of endpoints (onset of spasms, loss of righting response, etc.) can be difficult to measure consistently, especially with smaller insects. To resolve this problem, Lighton and Turner (2004) developed a new technique: thermolimit respirometry (TLR). TLR combines real time measurements of both metabolism (V·CO2) and activity to provide two independent, objective measures of CTmax. However, several questions still remain regarding the precision of TLR and how accurate it is in relation to traditional methods. Therefore, we evaluated CTmax of bed bugs using both traditional (visual) methods and TLR at three important metabolic periods following feeding (1d, 9d, and 21d). Both methods provided similar estimates of CTmax, although traditional methods produced consistently lower values (0.7-1°C lower than TLR). Despite similar levels of precision, TLR provided a more complete profile of thermal tolerance, describing changes in metabolism and activity leading up to the CTmax, not available through traditional methods. In addition, feeding status had a significant effect on bed bug CTmax, with bed bugs starved 9d (45.19[±0.20]°C) having the greatest thermal tolerance, followed by bed bugs starved 1d (44.64[±0.28]°C), and finally bed bugs starved 21d (44.12[±0.28]°C). Accuracy of traditional visual methods in relation to TLR is highly dependent on the selected endpoint; however, when performed correctly, both methods provide precise, accurate, and reliable estimations of CTmax.
Collapse
Affiliation(s)
- Zachary C DeVries
- Department of Entomology and Plant Pathology, 301 Funchess Hall, Auburn University, Auburn, AL 36849, USA; Department of Entomology, Campus Box 7613, North Carolina State University, Raleigh, NC 27695-7613, USA.
| | - Stephen A Kells
- Department of Entomology, 219 Hodson Hall, 1980 Folwell Ave., University of Minnesota, St. Paul, MN 55108, USA
| | - Arthur G Appel
- Department of Entomology and Plant Pathology, 301 Funchess Hall, Auburn University, Auburn, AL 36849, USA
| |
Collapse
|