@article{oai:nipr.repo.nii.ac.jp:00006204,
 author = {Kojima,Takahito and Kawabe,Ryo and Shirasu,Kunio and Naito,Yasuhiko},
 journal = {Polar bioscience},
 month = {Feb},
 note = {P(論文), To estimate the physiological condition or metabolic rate simultaneously with swimming behavior, we recorded a continuous electrocardiogram (ECG) in freely swimming fish, red sea bream Pagrus major, in a net pen during a 24h period. Swimming speed, swimming depth, and the bioelectric potential of the heart in the test fish were recorded with a micro data-logger. It is difficult to eliminate electric noise while recording ECGs of actively swimming fish. In the present experiment, we attached electrodes to two points on the ventral surface and successfully obtained data. Two types of micro data-loggers (one for recording ECG and another for swimming speed and depth) were attached to the dorsal side of the fish. The red sea bream swam slowly ( <1 total length/s) and stayed deeper in the net pen during most of the day, except for frequent burst of speed and vertical movements around dawn. An analysis of heartbeat variability, showed that high-frequency components, representing vagal (parasympathetic) nerve activity, rose only around midnight.},
 pages = {104--111},
 title = {Preliminary study on heartbeats and swimming behavior of free-ranging fish, red sea bream Pagrus major, measured with newly developed micro data-logger},
 volume = {16},
 year = {2003}
}