Authors: Kevin T Bilyk Clive W Evans Arthur L DeVries
Publish Date: 2012/05/04
Volume: 35, Issue: 9, Pages: 1447-1451
Abstract
Many ectotherms rapidly acquire a shortlived increase in heat tolerance following a heat shock This capacity to heat harden has been noted in a number of temperate fishes but it is unknown whether it can also be found among the stenothermal Antarctic notothenioid fishes To investigate specimens of six notothenioid species were first brought to their critical thermal maxima CTMax and then following a recovery period of 4–24 h a second CTMax was determined for each species to test for an increase in heat tolerance All six species showed a significant increase over their initial CTMaxs providing evidence for the existence of heat hardening in notothenioids The magnitude of this increase ranged from 06 ± 029 to 18 °C ± 045 comparable to previously reported values from several temperate fishes and amphibians This suggests that the heat hardening of Antarctic notothenioids remains undiminished despite their limited heat tolerance and provides further evidence that these fishes retain plasticity in their responses to heat despite their historical residence in a constant cold environmentThe authors would like to thank the crew of R/V LM Gould the contractors and employees of the Raytheon Polar Services Corporation and staff and colleagues at Scott Base Additional thanks go to Lauren G Fields for determining CTMaxs in G acuticeps Funding for this work was provided by NSF Office of Polar Programs grant OPPAnt0231006 to AL DeVries and CHC Cheng
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