scholarly journals Temperature-dependence of metabolic rate in tropical and temperate aquatic insects: support for the Climate Variability Hypothesis in mayflies but not stoneflies

2019 ◽  
Author(s):  
Alisha A. Shah ◽  
H. Arthur Woods ◽  
Justin C. Havird ◽  
Andrea C. Encalada ◽  
Alexander S. Flecker ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Rocky Mountains ◽  
Aquatic Insects ◽  
Evolutionary History ◽  
Thermal Sensitivity ◽  
Elevation Gradient ◽  
Standard Metabolic Rate ◽  
Tropical Andes ◽  
Know How ◽  
Increasing Temperature

AbstractA fundamental gap in climate change vulnerability research is an understanding of the relative thermal sensitivity of ectotherms. Aquatic insects are vital to stream ecosystem function and biodiversity but insufficiently studied with respect to their thermal physiology. With global temperatures rising at an unprecedented rate, it is imperative that we know how aquatic insects respond to increasing temperature and whether these responses vary among taxa, latitudes, and elevations. We evaluated the thermal sensitivity of standard metabolic rate in stream-dwelling baetid mayflies and perlid stoneflies across a ~2,000 m elevation gradient in the temperate Rocky Mountains in Colorado, U.S.A., and the tropical Andes in Napo, Ecuador. We used temperature-controlled water baths and microrespirometry to estimate changes in oxygen consumption. Tropical mayflies generally exhibited greater thermal sensitivity in metabolism compared to temperate mayflies; tropical mayfly metabolic rates increased more rapidly with temperature and the insects more frequently exhibited behavioral signs of thermal stress. By contrast, temperate and tropical stoneflies did not clearly differ. Varied responses to temperature among baetid mayflies and perlid stoneflies may reflect differences in evolutionary history or ecological roles as herbivores and predators, respectively. Our results show that there is physiological variation across elevations and species and that low elevation tropical mayflies may be especially imperiled by climate warming. Given such variation among species, broad generalizations about the vulnerability of tropical ectotherms should be made more cautiously.

Standard metabolic rate and preferred body temperatures in some Australian pythons

1998 ◽  
Vol 46 (4) ◽  
pp. 317 ◽  
Author(s):  
Gavin S. Bedford ◽  
Keith A. Christian
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Thermal Sensitivity ◽  
Standard Metabolic Rate ◽  
Allometric Equations ◽  
Metabolic Rates ◽  
Body Temperatures ◽  
Daily Cycle ◽  
Preferred Body Temperature

Pythons have standard metabolic rates and preferred body temperatures that are lower than those of most other reptiles. This study investigated metabolic rates and preferred body temperatures of seven taxa of Australian pythons. We found that Australian pythons have particularly low metabolic rates when compared with other boid snakes, and that the metabolic rates of the pythons did not change either seasonally or on a daily cycle. Preferred body temperatures do vary seasonally in some species but not in others. Across all species and seasons, the preferred body temperature range was only 4.9˚C. The thermal sensitivity (Q10) of oxygen consumption by pythons conformed to the established range of between 2 and 3. Allometric equations for the pooled python data at each of the experimental temperatures gave an equation exponent of 0.72–0.76, which is similar to previously reported values. By having low preferred body temperatures and low metabolic rates, pythons appear to be able to conserve energy while still maintaining a vigilant ‘sit and wait’ predatory existence. These physiological attributes would allow pythons to maximise the time they can spend ‘sitting and waiting’ in the pursuit of prey.

Field-Testing a Standard Metabolic Rate Estimation Technique for Eastern Red-Backed Salamanders

2016 ◽  
Vol 50 (1) ◽  
pp. 138-144
Author(s):  
Patrick J Ruhl ◽  
Robert N Chapman ◽  
John B. Dunning
Keyword(s):  
Metabolic Rate ◽  
Field Testing ◽  
Standard Metabolic Rate ◽  
Estimation Technique ◽  
Rate Estimation

scholarly journals The benefit of being still: energy savings during winter dormancy in fish come from inactivity and the cold, not from metabolic rate depression

2018 ◽  
Vol 285 (1886) ◽  
pp. 20181593 ◽  
Author(s):  
Ben Speers-Roesch ◽  
Tommy Norin ◽  
William R. Driedzic
Keyword(s):  
Metabolic Rate ◽  
Fish Species ◽  
Energy Savings ◽  
Thermal Sensitivity ◽  
Resting Metabolic Rate ◽  
Winter Dormancy ◽  
Metabolic Rate Depression ◽  
Spontaneous Movement ◽  
Anoxic Waters ◽  
Physico Chemical

Winter dormancy is used by many animals to survive the cold and food-poor high-latitude winter. Metabolic rate depression, an active downregulation of resting cellular energy turnover and thus standard (resting) metabolic rate (SMR), is a unifying strategy underlying the persistence of organisms in such energy-limited environments, including hibernating endotherms. However, controversy exists about its involvement in winter-dormant aquatic ectotherms. To address this debate, we conducted simultaneous, multi-day measurements of whole-animal oxygen consumption rate (a proxy of metabolic rate) and spontaneous movement in a model winter-dormant marine fish, the cunner ( Tautogolabrus adspersus ). Winter dormancy in cunner involved a dampened diel rhythm of metabolic rate, such that a low and stable metabolic rate persisted throughout the 24 h day. Based on the thermal sensitivity ( Q 10 ) of SMR as well as correlations of metabolic rate and movement, the reductions in metabolic rate were not attributable to metabolic rate depression, but rather to reduced activity under the cold and darkness typical of the winter refuge among substrate. Previous reports of metabolic rate depression in cunner, and possibly other fish species, during winter dormancy were probably confounded by variation in activity. Unlike hibernating endotherms, and excepting the few fish species that overwinter in anoxic waters, winter dormancy in fishes, as exemplified by cunner, need not involve metabolic rate depression. Rather, energy savings come from inactivity combined with passive physico-chemical effects of the cold on SMR, demonstrating that thermal effects on activity can greatly influence temperature–metabolism relationships, and illustrating the benefit of simply being still in energy-limited environments.

scholarly journals Multigenerational exposure to elevated temperatures leads to a reduction in standard metabolic rate in the wild

2020 ◽  
Vol 34 (6) ◽  
pp. 1205-1214 ◽  
Author(s):  
Natalie Pilakouta ◽  
Shaun S. Killen ◽  
Bjarni K. Kristjánsson ◽  
Skúli Skúlason ◽  
Jan Lindström ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Elevated Temperatures ◽  
Standard Metabolic Rate ◽  
In The Wild

Energy expenditure for thermoregulation and locomotion in emperor penguins

1976 ◽  
Vol 231 (3) ◽  
pp. 903-912 ◽  
Author(s):  
B Pinshow ◽  
MA Fedak ◽  
DR Battles ◽  
K Schmidt-Nielsen
Keyword(s):  
Metabolic Rate ◽  
Energy Requirement ◽  
Thermal Conductance ◽  
Standard Metabolic Rate ◽  
High Energy ◽  
Breeding Cycle ◽  
Emperor Penguin ◽  
Energy Reserves ◽  
Ambient Temperatures ◽  
Emperor Penguins

During the antarctic winter emperor penguins (Aptenodytes forsteri) spend up to four mo fasting while they breed at rookeries 80 km or more from the sea, huddling close together in the cold. This breeding cycle makes exceptional demands on their energy reserves, and we therefore studied their thermoregulation and locomotion. Rates of metabolism were measured in five birds (mean body mass, 23.37 kg) at ambient temperatures ranging from 25 to -47 degrees C. Between 20 and -10 degrees C the metabolic rate (standard metabolic rate (SMR)) remained neraly constant, about 42.9 W. Below -10 degrees C metabolic rate increased lineraly with decreasing ambient temperature and at -47 degrees C it was 70% above the SMR. Mean thermal conductance below -10 degrees C was 1.57 W m-2 degrees C-1. Metabolic rate during treadmill walking increased linearly with increasing speed. Our data suggest that walking 200 km (from the sea to the rookery and back) requires less than 15% of the energy reserves of a breeding male emperor penguin initially weighing 35 kg. The high energy requirement for thermoregulation (about 85%) would, in the absence of huddling, probably exceed the total energy reserves.

Mitochondrial Proton Conductance, Standard Metabolic Rate and Metabolic Depression

2000 ◽  
pp. 413-430 ◽  
Author(s):  
Martin D. Brand ◽  
Tammie Bishop ◽  
Robert G. Boutilier ◽  
Julie St-Pierre
Keyword(s):  
Metabolic Rate ◽  
Standard Metabolic Rate ◽  
Metabolic Depression ◽  
Proton Conductance

scholarly journals Aerobic capacity influences the spatial position of individuals within fish schools

2011 ◽  
Vol 279 (1727) ◽  
pp. 357-364 ◽  
Author(s):  
Shaun S. Killen ◽  
Stefano Marras ◽  
John F. Steffensen ◽  
David J. McKenzie
Keyword(s):  
Metabolic Rate ◽  
Aerobic Capacity ◽  
Leading Edge ◽  
Standard Metabolic Rate ◽  
Fish Schools ◽  
Liza Aurata ◽  
Schooling Behaviour ◽  
In The Wild ◽  
Focal Fish ◽  
Spatial Positioning

The schooling behaviour of fish is of great biological importance, playing a crucial role in the foraging and predator avoidance of numerous species. The extent to which physiological performance traits affect the spatial positioning of individual fish within schools is completely unknown. Schools of juvenile mullet Liza aurata were filmed at three swim speeds in a swim tunnel, with one focal fish from each school then also measured for standard metabolic rate (SMR), maximal metabolic rate (MMR), aerobic scope (AS) and maximum aerobic swim speed. At faster speeds, fish with lower MMR and AS swam near the rear of schools. These trailing fish required fewer tail beats to swim at the same speed as individuals at the front of schools, indicating that posterior positions provide hydrodynamic benefits that reduce swimming costs. Conversely, fish with high aerobic capacity can withstand increased drag at the leading edge of schools, where they could maximize food intake while possibly retaining sufficient AS for other physiological functions. SMR was never related to position, suggesting that high maintenance costs do not necessarily motivate individuals to occupy frontal positions. In the wild, shifting of individuals to optimal spatial positions during changing conditions could influence structure or movement of entire schools.

Aspects of the Use of Den Trees by Arboreal and Scansorial Marsupials Inhabiting Montane Ash Forests in Victoria

1991 ◽  
Vol 39 (1) ◽  
pp. 57 ◽  
Author(s):  
DB Lindenmayer ◽  
RB Cunningham ◽  
MT Tanton ◽  
HA Nix
Keyword(s):  
Metabolic Rate ◽  
Standard Metabolic Rate ◽  
The Body ◽  
Large Species ◽  
Strongly Correlated ◽  
Emergence Time ◽  
Significant Preference ◽  
Field Metabolic Rate ◽  
Arboreal Marsupials ◽  
Selection Of

The time and height of emergence from den trees occupied by various species of arboreal marsupials inhabiting the montane ash forests of the Central Highlands of Victoria, in south-east Australia, were recorded from September 1988 to January 1989. There were significant differences in emergence time among most species of arboreal marsupials. Emergence time was strongly correlated with published values of body weight, field metabolic rate and standard metabolic rate. The entrance to the nest was higher in gliding species than those which are non-volant. Small species exhibited a significant preference for den sites with a hole as the entrance. The entrance of a den occupied by large species was typically a hole in a hollow branch or spout. The selection of den sites was related to the body size of the occupant. Differences in the type and height of the entrance to the nest, together with the time of emergence from the den, indicate partitioning of the nest tree resource between the various species inhabiting montane ash forests.

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