Tunas, including albacore, have a highly evolved circulatory system including countercurrent exchangers (rete mirabile) that act to reduce the loss of heat generated by increased muscular activity, allowing them to regulate their body temperature and ultimately, increase the effciency of their muscles.

Regarding Thunnus alalunga, Graham and Dickson (1981) established that it is in the 11.5-18ºC temperature range where, thanks to this physiological adaptation, albacore are able to keep stable their red muscle temperature and, to a lesser extent, also white muscle temperature. Within this ambient temperature, average estimated temperature of red muscle was 20.7ºC. Outside that range, albacore show a poorer thermorregulation capacity.

Additionally, albacore have higher blood pressure and volume than most of the other fish (Lai et al 1987).

Regarding swimming speed, juveniles swim at speeds of 57 cm/s whereas adults swim at speeds slower than 45 cm/s (Dotson, 1976). This high metabolic activity involves a high oxygen consumption. Bard (1982) estimated that albacore could not tolerate living in waters with an oxygen content lower than 2.5 ml/l. However, according to Sharp (1978), minimum tolerated values are 1.67 ml/l at 50 cm and 1.39 ml/l at 75 cm body length.