Thermoperiodism in Sea-run Cutthroat Trout ( Salmo clarki clarki)

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Science  25 Oct 1963:
Vol. 142, Issue 3591, pp. 486-488
DOI: 10.1126/science.142.3591.486


Thermal tolerances from square-wave cycled temperature acclimation were compared with those from constant acclimation temperatures. A response to the maximum temperature of the square-wave cycle occurred. The acclimation thermoperiod was varied from one-fourth to twice the 24-hour cycle, and a relative maximum of tolerance resulted for the 24-hour thermoperiod. This suggests physiological adaption to natural 24-hour thermoperiods.