Abstract
A cyprinid fish, Pseudogobio esocinus showed gradual bradycardia at oxygen saturation (%) of less than 29.7±4.6 (1.89±0.29ml/l of oxygen concentration), surfacing at 14.7±1.3 (0.94±0.09ml/l), drastic decrease of oxygen consumption at less than 14.2±0.8 (0.91±0.06ml/l) and asphyxia at 9.7±1.4 (0.62±0.09ml/l). The fish avoided water having low oxygen saturation of less than 54.0±5.4 (3.38±0.30ml/l), and markedly at less than 26.2±3.4 (1.62±0.16ml/l).
