Fig. 2. (A-F) Respirometry data from the present study of crucian carp (left), and previous studies (right) on goldfish (Fry and Hart, 1948) and Atlantic cod (Schurmann and Steffensen, 1997) showing the effect of temperature on _O2 (A) and (B), the alteration of critical oxygen concentration ([O₂]_crit), in response to different temperatures (C) and (D), and how the different species alter their oxygen uptake capabilities at different _O2 (E) and (F).