scholarly journals Trading heat and hops for water: Dehydration effects on locomotor performance, thermal limits, and thermoregulatory behavior of a terrestrial toad

2017 ◽  
Vol 7 (21) ◽  
pp. 9066-9075 ◽  
Author(s):  
Rodolfo C. O. Anderson ◽  
Denis V. Andrade
Keyword(s):  
Locomotor Performance ◽  
Thermoregulatory Behavior ◽  
Thermal Limits

scholarly journals Thermal niches of specialized gut symbionts: the case of social bees

2020 ◽  
Author(s):  
Tobin J. Hammer ◽  
Eli Le ◽  
Nancy A. Moran
Keyword(s):  
Thermoregulatory Behavior ◽  
Pollination Services ◽  
Thermal Biology ◽  
Social Bees ◽  
Thermal Limits ◽  
Host Health ◽  
Gut Symbionts ◽  
Heat Tolerant ◽  
Temperature Interactions

AbstractResponses to climate change are particularly complicated in species that engage in symbioses, as the niche of one partner may be modified by that of the other. We explored thermal traits in gut symbionts of honeybees and bumblebees, which are vulnerable to rising temperatures. In vitro assays of symbiont strains isolated from 16 host species revealed variation in thermal niches. Strains from bumblebees tended to be less heat-tolerant than those from honeybees, possibly due to bumblebees maintaining cooler nests or inhabiting cooler climates. Overall however, bee symbionts grew at temperatures up to 44 °C and withstood temperatures up to 52 °C, at or above the upper thermal limits of their hosts. While heat-tolerant, most strains of the symbiont Snodgrassella grew relatively slowly below 35 °C, perhaps because of adaptation to the elevated body temperatures that bees maintain through thermoregulation. In a gnotobiotic bumblebee experiment, Snodgrassella was unable to consistently colonize bees reared below 35 °C under conditions that limit thermoregulation. Thus, host thermoregulatory behavior appears important in creating a warm microenvironment for symbiont establishment. Bee-microbiome-temperature interactions could affect host health and pollination services, and inform research on the thermal biology of other specialized gut symbionts, such as those of humans.

Dealing with hot rocky environments: Critical thermal maxima and locomotor performance in Leptodactylus lithonaetes (Anura: Leptodactylidae)

2019 ◽  
pp. 155-161 ◽  
Author(s):  
Ivan Beltran
Keyword(s):  
Environmental Temperature ◽  
Extreme Temperature ◽  
Effect Of Temperature ◽  
Maximum Speed ◽  
Locomotor Performance ◽  
Extreme Temperatures ◽  
Physiological Limits ◽  
Fitness Consequences ◽  
Thermal Maximum ◽  
Environmental Temperatures

Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.

Global temperature and life

2017 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Life Cycle ◽  
Marine Invertebrates ◽  
Natural World ◽  
Death Valley ◽  
Cell Interior ◽  
Ground Temperatures ◽  
Thermal Limits ◽  
Air Temperatures ◽  
Continental Shelves ◽  
Multicellular Organisms

The extreme meteorological surface air temperatures recorded to date are –89.2 oC in Antarctica, and 56.7 oC in Death Valley, California. Ground temperatures can be higher or lower than these air temperatures. The bulk of oceanic water is cold (< 4 oC) and thermally stable. Whilst data on limits to survival attract considerable attention, the thermal limits to completion of the life cycle (which define the limits to life) are much less well known. Currently identified upper thermal limits for growth are 122 oC for archaeans, 100 oC for bacteria and ~60 oC for unicellular eukaryotes. No unicells appear to grow below –20 oC, a limit that is probably set by dehydration-linked vitrification of the cell interior. The lower thermal limits for survival in multicellular organisms in the natural world extend to at least –70 oC. However in all cases known to date, completion of the life cycle requires summer warmth and the lowest temperature for completion of a multicellular eukaryote life cycle appears to be ~0 oC for invertebrates in glacial meltwater and ~–2 oC for marine invertebrates and fish living on the continental shelves around Antarctica.

Thermal limits in the face of infectious disease: how important are pathogens?

2021 ◽  
Author(s):  
Tobias E. Hector ◽  
Carla M. Sgrò ◽  
Matthew D. Hall
Keyword(s):  
Infectious Disease ◽  
Thermal Limits ◽  
The Face

scholarly journals Male fertility thermal limits predict vulnerability to climate warming

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Belinda van Heerwaarden ◽  
Carla M. Sgrò
Keyword(s):  
Climate Warming ◽  
Experimental Evolution ◽  
Male Fertility ◽  
Extinction Risk ◽  
Conservation Strategies ◽  
Tropical Species ◽  
Adaptive Responses ◽  
Widespread Species ◽  
Thermal Limits ◽  
Critical Thermal Limits

AbstractForecasting which species/ecosystems are most vulnerable to climate warming is essential to guide conservation strategies to minimize extinction. Tropical/mid-latitude species are predicted to be most at risk as they live close to their upper critical thermal limits (CTLs). However, these assessments assume that upper CTL estimates, such as CTmax, are accurate predictors of vulnerability and ignore the potential for evolution to ameliorate temperature increases. Here, we use experimental evolution to assess extinction risk and adaptation in tropical and widespread Drosophila species. We find tropical species succumb to extinction before widespread species. Male fertility thermal limits, which are much lower than CTmax, are better predictors of species’ current distributions and extinction in the laboratory. We find little evidence of adaptive responses to warming in any species. These results suggest that species are living closer to their upper thermal limits than currently presumed and evolution/plasticity are unlikely to rescue populations from extinction.

scholarly journals Thermal limits for flight activity of field-collected Culicoides in the United Kingdom defined under laboratory conditions

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Laura A. Tugwell ◽  
Marion E. England ◽  
Simon Gubbins ◽  
Christopher J. Sanders ◽  
Jessica E. Stokes ◽  
...  
Keyword(s):  
Companion Animals ◽  
Flight Activity ◽  
Cold Temperature ◽  
Threshold Temperature ◽  
Thermal Limits ◽  
Laboratory Conditions ◽  
North East ◽  
Temperature Thresholds ◽  
South East England ◽  
The Uk

Abstract Background Culicoides biting midges (Diptera: Ceratopogonidae) are biological vectors of internationally important arboviruses and inflict biting nuisance on humans, companion animals and livestock. In temperate regions, transmission of arboviruses is limited by temperature thresholds, in both replication and dissemination of arboviruses within the vector and in the flight activity of adult Culicoides. This study aims to determine the cold-temperature thresholds for flight activity of Culicoides from the UK under laboratory conditions. Methods Over 18,000 Culicoides adults were collected from the field using 4 W down-draught miniature ultraviolet Centers for Disease Control traps. Populations of Culicoides were sampled at three different geographical locations within the UK during the summer months and again in the autumn at one geographical location. Activity at constant temperatures was assessed using a bioassay that detected movement of adult Culicoides towards an ultraviolet light source over a 24-h period. Results The proportion of active adult Culicoides increased with temperature but cold temperature thresholds for activity varied significantly according to collection season and location. Populations dominated by the subgenus Avaritia collected in South East England had a lower activity threshold temperature in the autumn (4 °C) compared with populations collected in the summer (10 °C). Within the subgenus Avaritia, Culicoides scoticus was significantly more active across all temperatures tested than Culicoides obsoletus within the experimental setup. Populations of Culicoides impunctatus collected in the North East of England were only active once temperatures reached 14 °C. Preliminary data suggested flight activity of the subgenus Avaritia does not differ between populations in South East England and those in the Scottish Borders. Conclusions These findings demonstrate seasonal changes in temperature thresholds for flight and across different populations of Culicoides. These data, alongside that defining thresholds for virus replication within Culicoides, provide a primary tool for risk assessment of arbovirus transmission in temperate regions. In addition, the study also provides a comparison with thermal limits derived directly from light-suction trapping data, which is currently used as the main method to define adult Culicoides activity during surveillance.

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