The first of a series of papers from the Palmer station visit last year have been published in JEB. One of the goals was to measure cardiac output (how much blood the heart pumps per minute) since previous measurements were every variable and in some cases reported very high cardiac outputs, indicating that these fish did were pumping at or close to the maximum capacity. This would leave little room for changes and therefore they would be vulnerable for climate change that will increase the water temperature and increase the demand on the heart.  What we found was something different, the Blackfin icefish (Chaenocephalus aceratus) had a cardiac output that is just marginally higher compared to other Antarctic fish species and they had no short term problems with acute temperature increases