Estimation of the metabolic rate of wild red sea bream Pagrus major in different water temperatures

Two experiments were executed to investigate the correlation among water te mperature, metabolic rate and swimming behavior of red sea bream Pagrus maj or. In the former experiment, the relationship between oxygen consumption a nd water temperature was measured in laboratory respirometry trials. The re sult shelved water temperature (T, degrees C) has the following correlation with oxygen consumption (OC, mg min.(-1) kg(-1)); OC=1.47+0.01x1.22(T), R= 0.92. In the latter experiment, a wild adult fish was tracked in the open s ea using an ultrasonic transmitter to record the horizontal migration paths , vertical swimming trajectory and ambient water temperature. The fish rest ed on the bottom during the day. While at night, it swam up and down within the depth range 30 to 80 m. The ambient water temperature ranged from 18.5 to 22.9 degrees C. In the period of resting, the red sea bream was estimat ed to consume oxygen ranging from 1.91 to 2.55 mg min.(-1) kg(-1), in the o pen ocean. During the experimental period of 28 days, the fish remained wit hin a shoal and moved only small horizontal distances. Fluctuation of ambie nt water temperature seemed to have little effect on the swimming behavior of red sea bream.