scholarly journals Oxygen limitation of thermal tolerance defined by cardiac and ventilatory performance in spider crab, Maja squinado

2000 ◽  
Vol 279 (5) ◽  
pp. R1531-R1538 ◽  
Author(s):  
Markus Frederich ◽  
Hans O. Pörtner
Keyword(s):  
Thermal Tolerance ◽  
Aerobic Performance ◽  
Spider Crab ◽  
Critical Temperatures ◽  
Physiological Processes ◽  
Anaerobic Energy ◽  
Distribution Limits ◽  
On Line ◽  
Ventilation Rates ◽  
Thermal Limitation

Geographic distribution limits of ectothermal animals appear to be correlated with thermal tolerance thresholds previously identified from the onset of anaerobic metabolism. Transition to these critical temperatures was investigated in the spider crab ( Maja squinado) with the goal of identifying the physiological processes limiting thermal tolerance. Heart and ventilation rates as well as Po 2 in the hemolymph were recorded on-line during progressive temperature change between 12 and 0°C (1°C/h) and between 12 and 40°C (2°C/h). Lactate and succinate were measured in tissues and hemolymph after intermediate or final temperatures were reached. High levels of hemolymph oxygenation suggest that an optimum range of aerobic performance exists between 8 and 17°C. Thermal limitation may already set in at the transition from optimum to pejus (pejus = turning worse, progressively deleterious) range, characterized by the onset of a decrease in arterial Po 2 due to reduced ventilatory and cardiac performance. Hemolymph Po 2 values fell progressively toward both low and high temperature extremes until critical temperatures were reached at ∼1 and 30°C, as indicated by low Po 2 and the onset of anaerobic energy production by mitochondria. In conclusion, the limited capacity of ventilation and circulation at extreme temperatures causes insufficient O2 supply, thereby limiting aerobic scope and, finally, thermal tolerance.

scholarly journals Impact of anthropogenic ocean acidification on thermal tolerance of the spider crab <i>Hyas araneus</i>

2009 ◽  
Vol 6 (2) ◽  
pp. 2837-2861 ◽  
Author(s):  
K. Walther ◽  
F. J. Sartoris ◽  
C. Bock ◽  
H. O. Pörtner
Keyword(s):  
Heart Rate ◽  
Thermal Tolerance ◽  
Thermal Sensitivity ◽  
Co2 Concentration ◽  
Spider Crab ◽  
Thermal Window ◽  
Co2 Levels ◽  
Hyas Araneus ◽  
Q10 Values ◽  
Critical Temperature Tc

Abstract. Future scenarios project combined developments of elevated CO2 concentrations and global warming and their impact on marine ecosystems. The synergistic impact of both factors was addressed by studying the effect of CO2 accumulation on thermal tolerance of the cold-eurythermal spider crab Hyas araneus. Animals were exposed to present day normocapnia (380 ppm CO2), CO2 levels expected towards 2100 (710 ppm) and beyond (3000 ppm). Heart rate and haemolymph PO2 (PeO2) were measured during progressive short term cooling from 10 to 0°C and during warming from 10 to 25°C. An increase of PeO2 occurred during cooling with highest values reached at 0°C under all three CO2 levels. Heart rate increased during warming until a critical temperature (Tc) was reached. The putative Tc under normocapnia was presumably >25°C, from where it fell to 23.5°C under 710 ppm and then 21.1°C under 3000 ppm. At the same time, thermal sensitivity, as seen in the Q10 values of heart rate, rose with increasing CO2 concentration in the warmth. Our results suggest a narrowing of the thermal window of Hyas araneus under moderate increases in CO2 levels by exacerbation of the heat or cold induced oxygen and capacity limitation of thermal tolerance.

scholarly journals Global analysis of thermal tolerance and latitude in ectotherms

2010 ◽  
Vol 278 (1713) ◽  
pp. 1823-1830 ◽  
Author(s):  
Jennifer M. Sunday ◽  
Amanda E. Bates ◽  
Nicholas K. Dulvy
Keyword(s):  
Thermal Tolerance ◽  
Large Scale ◽  
Global Analysis ◽  
Marine Species ◽  
Seasonal Temperature ◽  
Geographical Patterns ◽  
Thermal Limits ◽  
Physiological Processes ◽  
Seasonal Temperature Variation ◽  
Do So

A tenet of macroecology is that physiological processes of organisms are linked to large-scale geographical patterns in environmental conditions. Species at higher latitudes experience greater seasonal temperature variation and are consequently predicted to withstand greater temperature extremes. We tested for relationships between breadths of thermal tolerance in ectothermic animals and the latitude of specimen location using all available data, while accounting for habitat, hemisphere, methodological differences and taxonomic affinity. We found that thermal tolerance breadths generally increase with latitude, and do so at a greater rate in the Northern Hemisphere. In terrestrial ectotherms, upper thermal limits vary little while lower thermal limits decrease with latitude. By contrast, marine species display a coherent poleward decrease in both upper and lower thermal limits. Our findings provide comprehensive global support for hypotheses generated from studies at smaller taxonomic subsets and geographical scales. Our results further indicate differences between terrestrial and marine ectotherms in how thermal physiology varies with latitude that may relate to the degree of temperature variability experienced on land and in the ocean.

Impact of age, sex, and size on the thermal tolerance of the adult black soldier fly (Diptera: Stratiomyidae)

2021 ◽  
pp. 1-12
Author(s):  
C. Li ◽  
N.F. Addeo ◽  
T.W. Rusch ◽  
A.J. Dickerson ◽  
A.M. Tarone ◽  
...  
Keyword(s):  
Mass Production ◽  
Thermal Tolerance ◽  
Egg Production ◽  
Thermal Stresses ◽  
Mass Rearing ◽  
Critical Temperatures ◽  
Younger Adults ◽  
Black Soldier Fly ◽  
The Difference ◽  
Age And Sex

Thermal stresses from both environmental conditions and organismal crowding are common in mass production of the black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae). In this study, upper and lower critical thermal (CT) limits (i.e. knockdown CTmax and CTmin) for the adult black soldier fly were determined. Impacts of size, age, and sex on these critical temperatures were also assessed. The CTmax ranged from 45.0-51.0 °C with larger and older adults having a ~1 °C higher CTmax than smaller and younger adults. However, no differences in the CTmax were found between sexes, regardless of age or size. The CTmin ranged from 8.0 to 13.0 °C with larger and older females having a ~1 °C higher CTmin than males and smaller or younger females. While reporting the upper and lower critical temperatures, this study also revealed the thermal breadth (i.e. the range of body temperatures over which organisms can locomote) for adult black soldier flies across age, sex, and size. Based on these data, and when recognising not all fly populations are the same, mass-rearing facilities should determine the CTmax and CTmin for their fly population in order to optimise mating and fertile egg production, and ultimately maximise profits and sales. One degree of temperature can be the difference between success and failure in industrialised facilities.

scholarly journals Improved heat tolerance in air drives the recurrent evolution of air-breathing

2014 ◽  
Vol 281 (1782) ◽  
pp. 20132927 ◽  
Author(s):  
Folco Giomi ◽  
Marco Fusi ◽  
Alberto Barausse ◽  
Bruce Mostert ◽  
Hans-Otto Pörtner ◽  
...  
Keyword(s):  
Thermal Tolerance ◽  
Evolutionary Biology ◽  
High Water ◽  
Aerobic Performance ◽  
Air Breathing ◽  
Thermal Niche ◽  
Key Innovation ◽  
Animal Phyla ◽  
The Tropics ◽  
Environmental Temperatures

The transition to air-breathing by formerly aquatic species has occurred repeatedly and independently in fish, crabs and other animal phyla, but the proximate drivers of this key innovation remain a long-standing puzzle in evolutionary biology. Most studies attribute the onset of air-breathing to the repeated occurrence of aquatic hypoxia; however, this hypothesis leaves the current geographical distribution of the 300 genera of air-breathing crabs unexplained. Here, we show that their occurrence is mainly related to high environmental temperatures in the tropics. We also demonstrate in an amphibious crab that the reduced cost of oxygen supply in air extends aerobic performance to higher temperatures and thus widens the animal's thermal niche. These findings suggest that high water temperature as a driver consistently explains the numerous times air-breathing has evolved. The data also indicate a central role for oxygen- and capacity-limited thermal tolerance not only in shaping sensitivity to current climate change but also in underpinning the climate-dependent evolution of animals, in this case the evolution of air-breathing.

scholarly journals Impact of anthropogenic ocean acidification on thermal tolerance of the spider crab <i>Hyas araneus</i>

2009 ◽  
Vol 6 (10) ◽  
pp. 2207-2215 ◽  
Author(s):  
K. Walther ◽  
F. J. Sartoris ◽  
C. Bock ◽  
H. O. Pörtner
Keyword(s):  
Heart Rate ◽  
Thermal Tolerance ◽  
Thermal Sensitivity ◽  
Co2 Concentration ◽  
Spider Crab ◽  
Ambient Temperatures ◽  
Thermal Window ◽  
Co2 Levels ◽  
Hyas Araneus ◽  
Q10 Values

Abstract. Future scenarios for the oceans project combined developments of CO2 accumulation and global warming and their impact on marine ecosystems. The synergistic impact of both factors was addressed by studying the effect of elevated CO2 concentrations on thermal tolerance of the cold-eurythermal spider crab Hyas araneus from the population around Helgoland. Here ambient temperatures characterize the southernmost distribution limit of this species. Animals were exposed to present day normocapnia (380 ppm CO2), CO2 levels expected towards 2100 (710 ppm) and beyond (3000 ppm). Heart rate and haemolymph PO2 (PeO2) were measured during progressive short term cooling from 10 to 0°C and during warming from 10 to 25°C. An increase of PeO2 occurred during cooling, the highest values being reached at 0°C under all three CO2 levels. Heart rate increased during warming until a critical temperature (Tc) was reached. The putative Tc under normocapnia was presumably >25°C, from where it fell to 23.5°C under 710 ppm and then 21.1°C under 3000 ppm. At the same time, thermal sensitivity, as seen in the Q10 values of heart rate, rose with increasing CO2 concentration in the warmth. Our results suggest a narrowing of the thermal window of Hyas araneus under moderate increases in CO2 levels by exacerbation of the heat or cold induced oxygen and capacity limitation of thermal tolerance.

scholarly journals Neural circuit robustness to acute, global physiological perturbations

2018 ◽  
Author(s):  
Jacob Ratliff ◽  
Eve Marder ◽  
Timothy O’Leary
Keyword(s):  
Critical Points ◽  
Neural Circuit ◽  
State Transitions ◽  
Neural Function ◽  
Quantitative Parameter ◽  
Critical Temperatures ◽  
Ph Values ◽  
Physiological Processes ◽  
Highly Sensitive ◽  
Physical Variables

AbstractNeural function depends on underlying physiological processes that are highly sensitive to physical variables such as temperature. However, some robustness to perturbations in these variables manifests at the circuit level, suggesting that circuit properties are organized to tolerate consistent changes in underlying parameters. We show that a crustacean pacemaker circuit is robust to two global perturbations - temperature and pH - that differentially alter circuit properties. Consistent with high variability in underlying circuit parameters, we find that the critical temperatures and pH values where circuit activity breaks down vary widely across animals. Despite variability in critical points the network state transitions at these critical points are consistent, implying that qualitative circuit dynamics are preserved across animals, in spite of high quantitative parameter variability. Surprisingly, robustness perturbations in pH only moderately affect temperature robustness. Thus, robustness to a global perturbation does not necessarily imply sensitivity to other global perturbations.

scholarly journals EFFECTS OF ELEVATED TEMPERATURE ON THE MORTALITY AND METABOLISM OF PACIFIC REEF CORALS

1970 ◽  
Vol 17 ◽  
pp. 71-72
Author(s):  
Stephen L. Coles
Keyword(s):  
Thermal Tolerance ◽  
Elevated Temperatures ◽  
Reef Coral ◽  
Temperature Tolerance ◽  
Temperature Adaptation ◽  
Critical Temperatures ◽  
Reef Corals ◽  
Annual Water ◽  
Physiological Tests ◽  
Upper Thermal Tolerance

The upper thermal tolerance limits of subtropical (Hawaiian) and tropical (Enewetak) reef corals were determined both in the field and under laboratory conditions. Enewetak corals routinely withstand temperatures up to 34°C whereas similar exposure time at 32°C kill their Hawaiian congeners. These differing upper thermal limits correspond to increases of + 4 - 5°C above the annual water temperature maxima at each location. Reef coral temperature tolerance is therefore closely adapted to the ambient ocean temperature conditions of a geographic location.Studies of temperature effect on reef coral photosynthesis (P) and respiration (R) also showed different patterns between locations. Same species shower greater autotrophic capability at elevated temperatures in Enewetak than Hawaii. Critical temperatures estimated as coinciding with P:R ratio values minimal to support long term functional autotrophy were 2-5°C higher for Enewetak than Hawaiian specimens, closely corresponding to observed differences in upper thermal tolerance. Results support a hypothesis of temperature adaptation capability for reef corals and suggest that short term physiological tests can predict relative differences in temperature tolerance among coral species.

scholarly journals Predicted impacts of climate warming on aerobic performance and upper thermal tolerance of six tropical freshwater fishes spanning three continents

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Dominique Lapointe ◽  
Michael S Cooperman ◽  
Lauren J Chapman ◽  
Timothy D Clark ◽  
Adalberto L Val ◽  
...  
Keyword(s):  
Climate Warming ◽  
Thermal Tolerance ◽  
Freshwater Fishes ◽  
Aerobic Performance ◽  
Tropical Freshwater ◽  
Upper Thermal Tolerance

scholarly journals Influence of Mouthguards on Physiological Responses in Rugby

2019 ◽  
Vol 03 (01) ◽  
pp. E25-E31 ◽  
Author(s):  
Antina Schulze ◽  
Stefan Kwast ◽  
Martin Busse
Keyword(s):  
Lung Function Test ◽  
Treadmill Running ◽  
Aerobic Performance ◽  
Energy Turnover ◽  
Ventilatory Parameters ◽  
Custom Made ◽  
Anaerobic Energy ◽  
Function Test ◽  
Rugby Players ◽  
Maximum Lactate

AbstractMouthguards (MGs) are highly recommended in rugby. Airway obstruction and a resulting decrease in power output are potential disadvantages of their usage. The aim of the study was to assess possible limitations of “vented” (MGV) and custom-made mouthguards (MGC) on rugby players’ performance. The MG effects were investigated in 13 male first-league rugby players ranging from 18–34 years old. First a lung function test was completed. Then a double incremental treadmill test was performed to measure maximum aerobic performance, ventilation, VO2, VCO2, heart rate, and lactate. Effects on sprint times (10 and 40 m) and countermovement jumps were also investigated. Peak flow values were significantly decreased with MGV by about 0.9 l/s. Neither ventilatory parameters nor oxygen uptake were affected by either of the mouthguards. Maximum lactate was significantly decreased in both MG types vs. no MG use. The maximum running velocity was similar in all tests. The aerobic energy turnover was moderately increased with the MGC and MGV. No effects were seen on sprint times or jump tests. Although neither type of mouthguard had a significant impact on maximum performance in treadmill running, the anaerobic energy turnover was decreased.

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