Impact of Changing Temperature on Critical Thermal Maximum and  Metabolic Rate of Uca perplexa and Uca crassipes

AbstractThe capacity of ectotherms to cope with rising temperatures associated with climate change is a significant conservation concern as the rate of warming is likely too fast for adaptation to occur in some populations. Transgenerational plasticity, if present, could potentially buffer some of the negative impacts of warming on future generations. We examined transgenerational plasticity in lake trout to assess their inter-generational potential to cope with anticipated warming. We acclimated adult lake trout to cold or warm temperatures for several months, then bred them to produce offspring from parents of matched and mismatched temperatures. At the fry stage, offspring were also acclimated to cold or warm temperatures and their thermal performance was assessed by measuring their critical thermal maximum and metabolic rate during an acute temperature challenge. Overall, transgenerational plasticity was evident: thermal performance of offspring reflected both maternal and paternal environmental conditions, and offspring performed better when their environment matched that of their parents. There was little variation in offspring critical thermal maximum or peak metabolic rate, although cold-acclimated offspring from warm-acclimated parents exhibited elevated standard metabolic rates, suggesting that transgenerational effects can be detrimental when parent and offspring environments mismatch. These results demonstrate both the occurrence and limitations of transgenerational plasticity in a coldwater salmonid in response to elevated temperature, as well as potential ecological risks associated with transgenerational plasticity when an environmental change experienced by the parents does not persist with the next generation.

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Thermal Acclimation to the Highest Natural Ambient Temperature Compromises Physiological Performance in Tadpoles of a Stream-Breeding Savanna Tree Frog

Frontiers in Physiology ◽

10.3389/fphys.2021.726440 ◽

2021 ◽

Vol 12 ◽

Author(s):

Leonardo S. Longhini ◽

Lucas A. Zena ◽

Elias T. Polymeropoulos ◽

Aline C. G. Rocha ◽

Gabriela da Silva Leandro ◽

...

Keyword(s):

Heart Rate ◽

Metabolic Rate ◽

Thermal Acclimation ◽

Future Climate Change ◽

Tree Frog ◽

Critical Thermal Maximum ◽

Physiological Performance ◽

Thermal Maximum ◽

Before And After ◽

Maximum Metabolic Rate

Amphibians may be more vulnerable to climate-driven habitat modification because of their complex life cycle dependence on land and water. Considering the current rate of global warming, it is critical to identify the vulnerability of a species by assessing its potential to acclimate to warming temperatures. In many species, thermal acclimation provides a reversible physiological adjustment in response to temperature changes, conferring resilience in a changing climate. Here, we investigate the effects of temperature acclimation on the physiological performance of tadpoles of a stream-breeding savanna tree frog (Bokermannohyla ibitiguara) in relation to the thermal conditions naturally experienced in their microhabitat (range: 18.8–24.6°C). We quantified performance measures such as routine and maximum metabolic rate at different test (15, 20, 25, 30, and 34°C) and acclimation temperatures (18 and 25°C). We also measured heart rate before and after autonomic blockade with atropine and sotalol at the respective acclimation temperatures. Further, we determined the critical thermal maximum and warming tolerance (critical thermal maximum minus maximum microhabitat temperature), which were not affected by acclimation. Mass-specific routine and mass-specific maximum metabolic rate, as well as heart rate, increased with increasing test temperatures; however, acclimation elevated mass-specific routine metabolic rate while not affecting mass-specific maximum metabolic rate. Heart rate before and after the pharmacological blockade was also unaffected by acclimation. Aerobic scope in animals acclimated to 25°C was substantially reduced, suggesting that physiological performance at the highest temperatures experienced in their natural habitat is compromised. In conclusion, the data suggest that the tadpoles of B. ibitiguara, living in a thermally stable environment, have a limited capacity to physiologically adjust to the highest temperatures found in their micro-habitat, making the species more vulnerable to future climate change.

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Acclimatory responses of thermal physiological performances in hatchling yellow pond turtles (Mauremys mutica)

Animal Biology ◽

10.1163/15707563-20191106 ◽

2020 ◽

Vol 70 (1) ◽

pp. 55-65

Author(s):

Hongliang Lu ◽

Yingchao Hu ◽

Shuran Li ◽

Wei Dang ◽

Yongpu Zhang

Keyword(s):

Metabolic Rate ◽

Resting Metabolic Rate ◽

Temperature Acclimation ◽

Critical Thermal Maximum ◽

Physiological Variables ◽

Thermal Maximum ◽

Mauremys Mutica ◽

Different Temperatures ◽

The Difference ◽

Critical Thermal Minimum

Abstract Temperature is a crucial environmental factor that can strongly impact animal physiology. Here, we acclimated hatchling of Asian yellow pond turtles (Mauremys mutica) to one of two different temperatures (25 or 30°C) for four weeks to determine temperature acclimation effects on their physiology. All four measured physiological variables (righting time, resting metabolic rate, critical thermal minimum and critical thermal maximum) were significantly affected by temperature acclimation. Turtles acclimated to 25°C righted themselves more slowly and had a lower mean metabolic rate than 30°C-acclimated turtles. Turtles acclimated to 25°C were more resistant to low temperatures, but less resistant to high temperatures than 30°C-acclimated turtles, as measured by critical thermal limits. The thermal resistance range (i.e., the difference between critical thermal minimum and maximum) did not differ between the two acclimation groups. Compared with other semi-aquatic turtles, M. mutica had relatively higher acclimation response ratios for its critical thermal minimum and critical thermal maximum. Our results indicate that acclimation to relatively moderate temperatures could also produce significant responses in the thermal physiology of turtles.

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The physiology of Venezillo arizonicus (Isopoda, Armadillidae): metabolism and thermal tolerance

Crustaceana ◽

10.1163/15685403-bja10026 ◽

2021 ◽

Vol 94 (2) ◽

pp. 159-175

Author(s):

Zechariah C. Harris ◽

Jonathan C. Wright

Keyword(s):

Metabolic Rate ◽

Thermal Tolerance ◽

Metabolic Regulation ◽

Activity Patterns ◽

Lethal Temperature ◽

Habitat Productivity ◽

Catabolic Rate ◽

Thermal Maximum ◽

Desert Habitat ◽

Reduced Temperature

Abstract Venezillo arizonicus (Mulaik & Mulaik, 1942) is the only oniscidean isopod native to the Southwest Desert Province of North America. In accordance with its desert habitat, we hypothesized that V. arizonicus would have a higher upper lethal temperature than mesic oniscideans. If oniscidean thermal tolerance is limited by an oxygen consumption-uptake mismatch (physiological hypoxia), as indicated by recent work with other land isopods, we further hypothesized that V. arizonicus would possess highly efficient pleopodal lungs, as defined by its capacity for metabolic regulation in reduced . Other adaptations to counter oxygen limitation at high temperatures could include reduced temperature sensitivity of metabolism (low ) and an overall reduction in metabolic rate. Thermal tolerance was measured using the progressive method of Cowles & Bogert and the catabolic rate of animals () was measured as a function of temperature and . The critical thermal maximum (CTmax) of winter-acclimatized animals was 43.0 ± 0.85°C, 1.6-2.6°C higher than published values for summer-acclimatized mesic oniscideans. The catabolic rate at 25°C was 1.50 ± 0.203 μl min−1 g−1, markedly lower than values determined for mesic Oniscidea (4-6 μl min−1 g−1) and was unaffected by hypoxia as low as 2% O2 (ca. 2 kPa). Catabolism was, however, quite sensitive to temperature, showing a mean of 2.58 over 25-42°C. The efficient pleopodal lungs and low metabolic rate of V. arizonicus will both tend to mitigate physiological hypoxia, consistent with the species’ high CTmax. A low catabolic rate may also be an adaptation to low habitat productivity and seasonally constrained activity patterns.

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Critical thermal maximum in mice

Journal of Applied Physiology ◽

10.1152/jappl.1976.40.5.683 ◽

1976 ◽

Vol 40 (5) ◽

pp. 683-687 ◽

Cited By ~ 34

Author(s):

G. L. Wright

Keyword(s):

Heat Stress ◽

Cooling Capacity ◽

Heating Time ◽

Critical Thermal Maximum ◽

Thermal Limit ◽

Ambient Temperatures ◽

Thermal Maximum ◽

Righting Reflex ◽

Colonic Temperature ◽

Extended Exposure

The critical thermal maximum (the colonic temperature of heat-induced convulsion and righting reflex loss) and thermoregulatory response of male mice were examined following I, exposure to colonic temperature (Tco) 42 degrees C; II, a single exposure to the critical thermal maximum (Tco 44 degrees C); AND III, acclimation at ambient temperatures of 15 or 30 degrees C for 14 days. The critical thermal maximum (CTM) was greater in 30 degrees C acclimated mice than 15 degrees C acclimated mice but was unchanged in mice surviving exposure to Tco 42 degrees C or the CTM. The heating time to apparent breakdown of thermoregulation coincident with an explosive rise in the Tco during exposure to ambient temperature 40.8 degrees C was increased (100%) during the 48-h period following exposure to Tco 42 degrees. It appeared that mice exposed to severe, short-term heat stress (Tco 42 degrees) undergo a compensatory increase in their thermoregulatory cooling capacity with little or no change in the upper temperature tolerated. The animals did, however, exhibit the capability for adaptive adjustments of the upper thermal limit during extended exposure to the more prolonged and less severe environmental heat stress of acclimation at 30 degrees C.

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Water temperature affects aggressive interactions in a Neotropical cichlid fish

Neotropical Ichthyology ◽

10.1590/1982-0224-20170081 ◽

2018 ◽

Vol 16 (1) ◽

Cited By ~ 7

Author(s):

Manuela L. Brandão ◽

Gisele Colognesi ◽

Marcela C. Bolognesi ◽

Roselene S. Costa-Ferreira ◽

Thaís B. Carvalho ◽

...

Keyword(s):

Aggressive Behavior ◽

Water Temperature ◽

Elevated Temperatures ◽

Cichlid Fish ◽

Aquatic Organisms ◽

Swimming Activity ◽

Critical Thermal Maximum ◽

Physiological Mechanisms ◽

Aggressive Interactions ◽

Thermal Maximum

ABSTRACT Changes in water temperature may affect the aggressive behavior of aquatic organisms, such as fish, either by changing some physiological mechanisms or by increasing the probability of encounters between individuals as a result of variation in their swimming activity. In our study, we evaluated the influence of increasing and decreasing temperature on the aggressive behavior of the Neotropical cichlid fish Cichlasoma paranaense. Firstly, we tested the critical thermal maximum (CTMax) tolerated by this species. Then, we tested the effect of decreasing or increasing the water temperature in 6o C (starting at 27° C) on the aggressive interactions of fish under isolation or housed in groups. We found a CTMax value of 39° C for C. paranaense. We also observe that a 6° C decrease in water temperature lowers swimming activity and aggressive interactions in both isolated and group-housed fish, as expected. On the other hand, the increase in temperature had no effect on the fish’s aggressive behavior, neither for isolated nor for grouped fish. We concluded that C. paranaense shows high tolerance to elevated temperatures and, in turn, it does not affect aggressive behavior. Nevertheless, we cannot dismiss possible effects of elevated temperatures on aggressive interactions over longer periods.

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