Cold Adaptation and Stenothermy in Antarctic Notothenioid Fishes: What Has Been Gained and What Has Been Lost?

Somero, George N.; Fields, Phillip A.; Hofmann, Gretchen E.; Weinstein, Randi B.; Kawall, Helena G.

doi:10.1007/978-88-470-2157-0_8

Cited by 27 publications

(16 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Alterations in mitochondrial function with temperature can contribute to trade-offs in energy budgets that in turn affect fish growth and fertility, and can ultimately influence population dynamics (Pörtner, 2002). However, some studies have indicated that the temperature at which liver and skeletal muscle mitochondrial respiration fail (T mt ) occurs above critical habitat temperatures (Pörtner et al, 2000;Pörtner, 2002;Somero et al, 1998;Weinstein and Somero, 1998). These studies, however, focused on maximal respiration capacities in terms of flux, with single electron inputs into respiratory chains, and did not use heart muscle or explore respirational efficiencies.…”

Section: Introductionmentioning

confidence: 99%

Could thermal sensitivity of mitochondria determine species distribution in a changing climate?

Iftikar

MacDonald

Baker

et al. 2014

Journal of Experimental Biology

View full text Add to dashboard Cite

For many aquatic species, the upper thermal limit (T max ) and the heart failure temperature (T HF ) are only a few degrees away from the species' current environmental temperatures. While the mechanisms mediating temperature-induced heart failure (HF) remain unresolved, energy flow and/or oxygen supply disruptions to cardiac mitochondria may be impacted by heat stress. Recent work using a New Zealand wrasse (Notolabrus celidotus) found that ATP synthesis capacity of cardiac mitochondria collapses prior to T HF . However, whether this effect is limited to one species from one thermal habitat remains unknown. The present study confirmed that cardiac mitochondrial dysfunction contributes to heat stress-induced HF in two additional wrasses that occupy cold temperate (Notolabrus fucicola) and tropical (Thalassoma lunare) habitats. With exposure to heat stress, T. lunare had the least scope to maintain heart function with increasing temperature. Heat-exposed fish of all species showed elevated plasma succinate, and the heart mitochondria from the cold temperate N. fucicola showed decreased phosphorylation efficiencies (depressed respiratory control ratio, RCR), cytochrome c oxidase (CCO) flux and electron transport system (ETS) flux. In situ assays conducted across a range of temperatures using naive tissues showed depressed complex II (CII) and CCO capacity, limited ETS reserve capacities and lowered efficiencies of pyruvate uptake in T. lunare and N. celidotus. Notably, alterations of mitochondrial function were detectable at saturating oxygen levels, indicating that cardiac mitochondrial insufficiency can occur prior to HF without oxygen limitation. Our data support the view that species distribution may be related to the thermal limits of mitochondrial stability and function, which will be important as oceans continue to warm.

show abstract

Section: Introductionmentioning

confidence: 99%

Could thermal sensitivity of mitochondria determine species distribution in a changing climate?

Iftikar

MacDonald

Baker

et al. 2014

Journal of Experimental Biology

View full text Add to dashboard Cite

show abstract

“…In addition, there may be differences in metabolic enzyme activities among closely related species living at different latitudes (Pierce and Crawford, 1997). Metabolic acclimation/acclimatisation may occur at the ultrastructural level, such as in mitochondrial numbers or cristae density (St Pierre et al, 1998;Guderley and St Pierre, 2002), or by changes in enzyme activity (Somero et al, 1998;Crawford et al, 1999). Enzyme activity may be altered in response to temperature by changing rates of transcription and enzyme concentrations Powers, 1989, 1992) or by expressing allozymes and isozymes with different thermal sensitivities (Lin and Somero, 1995;Fields and Somero, 1997).…”

Section: Introductionmentioning

confidence: 99%

Seasonal acclimatisation of muscle metabolic enzymes in a reptile(Alligator mississippiensis)

Seebacher

Guderley

Elsey

et al. 2003

Journal of Experimental Biology

123

View full text Add to dashboard Cite

The concept that reptiles regulate their body temperature by behavioural means, such as shuttling between sun and shade (Cowles and Bogert, 1944;Hertz et al., 1993), has become widely accepted in vertebrate thermal physiology. Behavioural adjustments enable many diurnal species of reptile to maintain high and stable body temperatures in the face of fluctuations in environmental temperatures (Avery, 1982;Seebacher et al., 1999). The importance of body temperature regulation is seen to lie in maximising the rates of temperature-sensitive physiological functions (Huey, 1982). The rates of chemical reactions, including those catalysed by enzymes, are dependent on the energetic state of the compounds involved, which in turn is strongly influenced by temperature. The rates of most physiological processes are, therefore, a direct function of the temperature of the organism. Thermoregulation that includes high metabolic heat production combined with effective insulation often allows endotherms to maintain an elevated body temperature within a narrow range (Lovegrove et al., 1991). The low metabolic rates of reptiles make metabolic heat production negligible, and regulation of body temperature is achieved by behavioural means such as microhabitat selection (Cowles Reptiles living in heterogeneous thermal environments are often thought to show behavioural thermoregulation or to become inactive when environmental conditions prevent the achievement of preferred body temperatures. By contrast, thermally homogeneous environments preclude behavioural thermoregulation, and ectotherms inhabiting these environments (particularly fish in which branchial respiration requires body temperature to follow water temperature) modify their biochemical capacities in response to long-term seasonal temperature fluctuations. Reptiles may also be active at seasonally varying body temperatures and could, therefore, gain selective advantages from regulating biochemical capacities. Hence, we tested the hypothesis that a reptile (the American alligator Alligator mississippiensis) that experiences pronounced seasonal fluctuations in body temperature will show seasonal acclimatisation in the activity of its metabolic enzymes. We measured body temperatures of alligators in the wild in winter and summer (N=7 alligators in each season), and we collected muscle samples from wild alligators (N=31 in each season) for analysis of metabolic enzyme activity (lactate dehydrogenase, citrate synthase and cytochrome c oxidase). There were significant differences in mean daily body temperatures between winter (15.66±0.43°C; mean ± S.E.M.) and summer (29.34±0.21°C), and daily body temperatures fluctuated significantly more in winter compared with summer. Alligators compensated for lower winter temperatures by increasing enzyme activities, and the activities of cytochrome c oxidase and lactate dehydrogenase were significantly greater in winter compared with summer at all assay temperatures. The activity of citrate synthase was significantly greater in the winter s...

show abstract

“…They can generally only survive at low temperatures, and within small temperature ranges, they are highly stenothermal (Somero et al 1996(Somero et al , 1998Peck and Conway 2000). This trait has come from evolution to a very stable temperature environment and carries with it many specific biochemical and physiological adaptations.…”

Section: Introductionmentioning

confidence: 99%

Metabolic Demand, Oxygen Supply, and Critical Temperatures in the Antarctic BivalveLaternula elliptica

Peck

Pörtner²,

Hardewig³

2002

Physiological and Biochemical Zoology

150

116

View full text Add to dashboard Cite

Oxygen consumption ( ), heartbeat rate and form, and cirMo 2 culating hemolymph oxygen content were measured in relation to temperature in the large Antarctic infaunal bivalve Laternula elliptica. After elevations in temperature from 0Њ to 3Њ, 6Њ, and then 9ЊC, and heartbeat rate rose to new levels, whereaṡ Mo 2 maximum circulating hemolymph oxygen content fell. At 0ЊC, was 19.6 mmol O 2 h Ϫ1 for a standard animal of 2-g tissuė Mo 2 ash-free dry mass, which equates to a 8.95-g tissue dry-mass or 58.4-g tissue wet-mass animal. Elevation of metabolism following temperature change had acute Q 10 values between 4.1 and 5, whereas acclimated figures declined from 3.4 (between 0Њ and 3ЊC) to 2.2 (3Њ-6ЊC) and 1.9 (6Њ-9ЊC). Heartbeat rate showed no acclimation following temperature elevations, with Q 10 values of 3.9, 3.2, and 4.3, respectively. Circulating hemolymph oxygen content declined from 0Њ to 3Њ and 6ЊC but stayed at a constant Po 2 (73-78 mmHg) and constant proportion (∼50%) of the oxygen content of the ambient water. At 9ЊC, and heartbeat rate both peaked at values 3.3 times thosė Mo 2 measured at 0ЊC, which may indicate aerobic scope in this species. After these peaks, both measures declined rapidly over the ensuing 5 d to the lowest measured in the study, and the bivalves began to die. Hemolymph oxygen content fell dramatically at 9ЊC to values between 2% and 12% of ambient water O 2 content and had a maximum Po 2 of around 20 mmHg. These data indicate an experimental upper lethal temperature of 9ЊC and a critical temperature, where a long-term switch to

show abstract

Cold Adaptation and Stenothermy in Antarctic Notothenioid Fishes: What Has Been Gained and What Has Been Lost?

Cited by 27 publications

References 34 publications

Could thermal sensitivity of mitochondria determine species distribution in a changing climate?

Could thermal sensitivity of mitochondria determine species distribution in a changing climate?

Seasonal acclimatisation of muscle metabolic enzymes in a reptile(Alligator mississippiensis)

Metabolic Demand, Oxygen Supply, and Critical Temperatures in the Antarctic BivalveLaternula elliptica

Contact Info

Product

Resources

About