Fig. 7. Archival tag record demonstrating fasting and feeding in a wild Pacific bluefin tuna (16 kg). Depth (black), peritoneal cavity temperature (T_b, red), and ambient temperature (T_a, blue) are shown. Day and night are represented as light and dark bars, respectively. In (A) regular feeding events are indicated by a rise in peritoneal cavity temperature resulting from digestion. In (B) a stable T_b elevated only slightly relative to T_a indicates the absence of feeding events for four days, followed by the resumption of feeding.