This work reports recent data on mechanisms of cold adaptation exhibited by the Antarctic teleostsTrematomus bernacchiiandChionodraco hamatus.Analysis of fatty acid in intestinal mucosa brush border suggested that an increase in unsaturated fatty acid could be a mechanism for the preservation of cell membrane integrity and functionality. The investigation of several transporters involved in the regulation of cell homeostasis (Na+/K+‐AT‐Pase, Na+‐D‐glucose cotransport, Na+/H+exchanger and Ca++‐AT‐Pase) showed kinetic characteristics that could explain part of the adaptation of these proteins to work at low temperature. The activity of carbonic anhydrase, involved in pH control both at intra‐cellular and systemic level, was related to plasma buffer capacity.