Effects of acclimation to elevated water temperature and hypoxia on thermal tolerance of the threatened Pugnose Shiner Notropis anogenus

2021 ◽  
Author(s):  
Laura H. McDonnell ◽  
Nicholas E. Mandrak ◽  
Saravpreet Kaur ◽  
Lauren J Chapman
Keyword(s):  
Elevated Temperature ◽  
Dissolved Oxygen ◽  
Climate Warming ◽  
Oxidative Metabolism ◽  
Thermal Tolerance ◽  
Cyprinid Fish ◽  
Critical Thermal Maximum ◽  
Thermal Maximum ◽  
Elevated Water ◽  
Hypoxia Acclimation

For freshwater fishes, elevated water temperatures associated with climate warming and hypoxia can co-occur and are likely to interact as both affect oxidative metabolism. We quantified the effects of acclimation to elevated temperature and hypoxia on the thermal tolerance of Pugnose Shiner (Notropis anogenus), a cyprinid fish threatened in its Canadian range. In one experiment, Pugnose Shiner underwent 2-week sequential acclimations to six increasing temperatures. Fish acclimated to warmer waters increased their critical thermal maximum (CTmax), while the agitation temperature (Tag) was 3.4°C lower than CTmax. In another experiment, fish were acclimated to three dissolved oxygen treatments (>95%, ~56% or ~40% air saturation) for 2 weeks, and tested under >95% and 40% conditions. CTmax was lower when measured under 40% for normoxia-acclimated fish, but not for hypoxia-acclimated fish. Hypoxia-acclimated fish had higher Tag and smaller agitation windows than normoxia-acclimated fish, suggesting that hypoxia acclimation improves aspects of thermal tolerance. We examine the plasticity of thermal tolerance of Pugnose Shiner, showing that they may be more vulnerable to high temperatures compared to other non-imperilled Notropis species.

The critical thermal maximum: history and critique

1997 ◽  
Vol 75 (10) ◽  
pp. 1561-1574 ◽  
Author(s):  
William I. Lutterschmidt ◽  
Victor H. Hutchison
Keyword(s):  
Thermal Tolerance ◽  
Critical Thermal Maximum ◽  
Comparative Physiology ◽  
Lethal Temperature ◽  
Heating Rates ◽  
Righting Response ◽  
Thermal Maximum ◽  
History Of ◽  
Using Data ◽  
Phylogenetic Method

We reviewed 725 papers published since Cowles and Bogert's paper on thermal tolerance (R.B. Cowles and C.M. Bogert. 1944. Bull. Am. Mus. Nat. Hist. 83: 261–296) to create a data base of studies that used critical thermal maximum or lethal-temperature methods. We found data from 388 of these papers to provide a historical and taxonomic review of various methodologies used in measuring tolerance of high temperature. We conducted this literature review of previous studies to (i) describe the history of the study of thermal tolerance and show the chronological trends in the use of lethal temperature and critical thermal maximum methods, (ii) illustrate the diversity of taxa used in thermal-tolerance studies, (iii) summarize the diversity of protocols (i.e., end points, heating rates, acclimations, etc.) used for determining thermal tolerance, (iv) provide physiological reasons why the onset of spasms is more meaningful biologically than the loss of righting response, and (v) discuss the difficulties in using data from studies in which widely divergent methods were used and the importance of obtaining comparative thermal-tolerance data for comparative physiology. The adoption of the onset of spasms as a standard end point would allow for valid comparisons of data from different studies and among taxa, an important consideration for current investigations of comparative physiology that use the comparative phylogenetic method.

scholarly journals Basal tolerance but not plasticity gives invasive springtails the advantage in an assemblage setting

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Laura M Phillips ◽  
Ian Aitkenhead ◽  
Charlene Janion-Scheepers ◽  
Catherine K King ◽  
Melodie A McGeoch ◽  
...  
Keyword(s):  
Phenotypic Plasticity ◽  
Thermal Tolerance ◽  
Indigenous Species ◽  
Critical Thermal Maximum ◽  
Desiccation Resistance ◽  
Physiological Trait ◽  
Egg Development ◽  
Egg Hatching ◽  
Thermal Maximum ◽  
Interspecific Comparisons

Abstract As global climates change, alien species are anticipated to have a growing advantage relative to their indigenous counterparts, mediated through consistent trait differences between the groups. These insights have largely been developed based on interspecific comparisons using multiple species examined from different locations. Whether such consistent physiological trait differences are present within assemblages is not well understood, especially for animals. Yet, it is at the assemblage level that interactions play out. Here, we examine whether physiological trait differences observed at the interspecific level are also applicable to assemblages. We focus on the Collembola, an important component of the soil fauna characterized by invasions globally, and five traits related to fitness: critical thermal maximum, minimum and range, desiccation resistance and egg development rate. We test the predictions that the alien component of a local assemblage has greater basal physiological tolerances or higher rates, and more pronounced phenotypic plasticity than the indigenous component. Basal critical thermal maximum, thermal tolerance range, desiccation resistance, optimum temperature for egg development, the rate of development at that optimum and the upper temperature limiting egg hatching success are all significantly higher, on average, for the alien than the indigenous components of the assemblage. Outcomes for critical thermal minimum are variable. No significant differences in phenotypic plasticity exist between the alien and indigenous components of the assemblage. These results are consistent with previous interspecific studies investigating basal thermal tolerance limits and development rates and their phenotypic plasticity, in arthropods, but are inconsistent with results from previous work on desiccation resistance. Thus, for the Collembola, the anticipated advantage of alien over indigenous species under warming and drying is likely to be manifest in local assemblages, globally.

scholarly journals The effects of repeat acute thermal stress on the critical thermal maximum (CTmax) and physiology of juvenile shortnose sturgeon (Acipenser brevirostrum)

2019 ◽  
Vol 97 (6) ◽  
pp. 567-572
Author(s):  
Brittany Bard ◽  
James D. Kieffer
Keyword(s):  
Thermal Stress ◽  
Thermal Tolerance ◽  
Thermal Stresses ◽  
Recovery Period ◽  
Critical Thermal Maximum ◽  
Shortnose Sturgeon ◽  
Acipenser Brevirostrum ◽  
Time Period ◽  
Thermal Maximum ◽  
Plasma Chloride

The shortnose sturgeon (Acipenser brevirostrum Lesueur, 1818) is a species of special concern in Canada, but little is known about their thermal biology. Information on the upper thermal tolerance of shortnose sturgeon becomes valuable for predicting future survival particularly with climate change and improving species management. Using a modified critical thermal maximum (CTmax) methodology, the objective is to determine whether previous thermal stress affects the thermal tolerance of juvenile shortnose sturgeon when exposed to a second thermal stress event. Prior exposure to thermal stress (CTmax1) did not affect the thermal tolerance (CTmax2) of juvenile shortnose sturgeon when a 24 h recovery period was allotted between tests. However, a significant increase in thermal tolerance occurred when the recovery time between the two thermal challenges was 1 h. Plasma glucose, lactate, and osmolality were all significantly affected by thermal stress, but values returned to control levels within 24 h. Hematocrit and plasma chloride concentrations were not significantly affected by thermal stress. All fish survived the CTmax testing. The data indicate that the thermal tolerance of juvenile shortnose sturgeon is modified when multiple thermal stresses occur closer together (1 h) but not if separated by a longer time period (24 h).

The critical thermal maximum: data to support the onset of spasms as the definitive end point

1997 ◽  
Vol 75 (10) ◽  
pp. 1553-1560 ◽  
Author(s):  
William I. Lutterschmidt ◽  
Victor H. Hutchison
Keyword(s):  
Thermal Tolerance ◽  
Phylogenetic Analyses ◽  
Critical Thermal Maximum ◽  
End Point ◽  
Righting Response ◽  
Thermal Maximum ◽  
Original Definition ◽  
Precise Measure ◽  
Definition Of ◽  
Shock Proteins

We provide data to support the onset of spasms (OS) as the definitive end point for determining thermal tolerance with the critical thermal maximum (CTMax). We measured the CTMax of 610 animals in three vertebrate classes, Actinopterygii, Amphibia, and Reptilia. All showed a significantly lower mean loss of righting response (LRR) than OS. Statistical evaluation of the variability associated with the end points LRR and OS also showed that OS is a more precise measure of thermal tolerance. OS is a more meaningful end point than LRR because it more closely fits the original definition of the critical thermal maximum (R.B. Cowles and C.M. Bogert. 1944. Bull. Am. Mus. Nat. Hist. 83: 261–296) and occurs at temperatures required for physiological responses, such as heat-hardening and perhaps the production of some heat-shock proteins. The adoption of OS as a standard end point would allow valid comparisons of data from different studies and among taxa, an important consideration for comparative phylogenetic analyses. However, we suggest that LRR should also be measured for comparisons with data from earlier studies.

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

Crustaceana ◽  
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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