Antarctic fish can survive prolonged exposure to elevated temperatures

Abstract

The Antarctic notothenioid Pagothenia borchgrevinki was collected from the stenothermal waters of McMurdo Sound in the summers of 2004, 2005 and 2006. Acclimation ability at 4°C was tested in healthy P. borchgrevinki and in individuals infected with x-cell gill disease. All healthy fish successfully acclimated to 4°C, establishing compensatory changes in resting oxygen consumption rate (R rest ) and critical swimming speed (U crit ) during a 1 month acclimation period, which were maintained during a longer, 6 month acclimation period. In contrast, individuals infected with xcell disease were unable to acclimate to 4°C, demonstrating significantly reduced survival rates compared with healthy individuals at 4°C. Measurements of R rest suggest that limitations in the ability of x-cell fish to uptake oxygen from the external milieu may have a negative effect on their survival at 4°C.

Is warmer better? Decreased oxidative damage in notothenioid fish after long-term acclimation to multiple stressors

“…In addition to changes seen at the cellular level, there is some evidence at the level of the whole organism that performance in these cold-adapted notothenioids may be optimal at elevated temperatures. Davison and colleagues have described similar effects of temperature on the RMR of P. borchgrevinki and also found that elevated temperature increases metabolic scope in these cold-adapted fish, with a maximal factorial scope occurring at +3°C (Seebacher et al, 2005;Lowe and Davison, 2006;Franklin et al, 2007;Robinson and Davison, 2008a;Robinson and Davison, 2008b). Thus, in the context of balancing energy expenditures and protecting metabolic scope, at least some Antarctic fish may perform better under future Southern Ocean conditions than previously predicted.…”

“…The initial spike in oxidative damage observed in this study along with the increased metabolic rates previously observed within the first week of acclimation (Robinson and Davison, 2008a;Robinson and Davison, 2008b;Strobel et al, 2012;Enzor et al, 2013) may signal a surge in protein synthesis and turnover as the cellular environment is restructured. The slow decline of metabolic rates seen in previous studies, connected with the precipitous drop-off in damaged proteins seen in this study, may in turn signal that the initial energy expenditure has led to a more stable cellular environment.…”

“…At the level of the whole organism, an early study from Somero and DeVries (Somero and DeVries, 1967) illustrated a narrow thermal window exists in which notothenioids can survive; however, more recent studies have shown that notothenioid fishes have retained the capacity to acclimate to increased temperatures (Seebacher et al, 2005;Franklin et al, 2007;Robinson and Davison, 2008a;Robinson and Davison, 2008b;Bilyk and DeVries, 2011;Bilyk et al, 2012). While these studies provide evidence that Antarctic fish are capable of acclimating to an increase in temperature, there is little information about the cost of acclimation on a cellular level.…”

“…The effects of increased temperature on Antarctic fish have been well documented (Somero and DeVries, 1967;Forster et al, 1987;Davison et al, 1990;Pörtner, 2008;Robinson and Davison, 2008a;Robinson and Davison, 2008b). At the level of the whole organism, an early study from Somero and DeVries (Somero and DeVries, 1967) illustrated a narrow thermal window exists in which notothenioids can survive; however, more recent studies have shown that notothenioid fishes have retained the capacity to acclimate to increased temperatures (Seebacher et al, 2005;Franklin et al, 2007;Robinson and Davison, 2008a;Robinson and Davison, 2008b;Bilyk and DeVries, 2011;Bilyk et al, 2012).…”

Triggers of the HSP70 stress response: environmental responses and laboratory manipulation in an Antarctic marine invertebrate (Nacella concinna)

“…These organisms live within a very restricted temperature regime, ranging from −1.86°C in winter to a summer maximum of −0.5°C in McMurdo Sound, Ross Sea and +1°C along the Antarctic Peninsula . Both the Antarctic fish and shallow water invertebrates are very stenothermal (Somero and DeVries 1967;Peck and Conway 2000;Peck et al 2009, under review), with many species having survivable temperature envelopes between 5°C and 12°C above the minimum sea temperature of −1.86°C (Peck 2002;Robinson and Davison 2008) and loss of critical biological functions at temperatures much below this (Peck et al 2004). In contrast to animals elsewhere in the world, when a range of these species were examined for a classical heat shock response, i.e.…”