Rigor Contractions in “Rested” and “Partially Exercised” Chinook Salmon White Muscle as Affected by Temperature

Time lapse video was used to determine the effects of temperature and fatigue on the development of rigor contractions in chinooksalmon ( Oncorhynchus tshawytscha ) white muscle. Minimal handling and chemical anaesthesia (AQUI‐STM) produced rested fish. After removal of one fillet from the rested fish, post‐mortem electrical stimulation of the carcass was used to partially exercise the remaining muscle. Specific strips of rested and partially exercised muscle were held in physiological saline at 0,4,6,8 and 12°C. Contraction onset and end were delayed by decreasing temperature in the rested treatment, but were unaffected in the partially exercised treatment. The final contracted length was affected by fatigue state and temperature.