1. Ultradian oscillations in the min and hr range on long-tem (24-hr) computerized recordings of heart rate in rainbow trout Oncorhynchus mykiss, acclimated to 5, 10 and 15-degrees-C water temperature, were investigated. Eight-hour duration time series derived from the heart mte recordings were analysed for their harmonic content in the ultradian band by spectral analysis.
2. A significant ultradian rhythm at around 0.011 cycles/min (approximately 91-min period) was detected in the power spectral density functions of all the 8-hr duration time series derived from the heart rate recordings at the three experimental water temperatures.
3. The spectral power of the ultradian oscillation detected in heart rate of trout was found to increase significantly with increasing temperature.
4. The possible endogenous origin of the ultradian rhythm detected in heart rate of Oncorhynchus mykiss is discussed.
|Number of pages||4|
|Journal||Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology|
|Publication status||Published - Oct 1993|