Fig. 2. Representative traces of air-breathing cycles in O. lacepedii. Inspired (V_I) and expired (V_E) volumes were obtained by subtracting a' from b' and a' from c', respectively. Note that V_E can be obtained only in (A), when the inspired air was kept intact in the buccal cavity until expiration. In (B), the fish released several bubbles prior to expiration. Body mass of fish used for A and B were 60.6 g and 81.1 g, respectively.