The limpet, Nacella concinna, collected from the Antarctic Peninsula (67 S), was incubated at -0.3 degrees C and 2.9 degrees C for 9 months to test if the previously reported absence of acclimation capacity in Antarctic marine ectotherms could be due to the extended time it takes for them to adjust their physiology to a new stable state. Acclimation was tested through acute measurements of upper lethal limit and a modified measure of tenacity, that tested muscle capacity by measuring the length of time that N. concinna were able to remain attached to the substratum at different temperatures. Both measures acclimated in response to incubation to the higher temperature. Lethal limits were elevated in N. concinna incubated at 2.9 degrees C (8.1 +/- 0.3 degrees C) compared to those incubated at -0.3 degrees C (6.9 +/- 0.4 degrees C). 2.9 degrees C incubated N. concinna also had a maximum tenacity at 2.1 degrees C. a higher temperature than the maximum tenacity of those incubated at -0.3 degrees C, which occurred at -1.0 degrees C. This study is the first to show that the Antarctic limpet can acclimate its physiology, but that it requires a greater period of time for acclimation to occur than previous studies have allowed for.