Changes in tension generation and ATPase activity in skinned muscle fibres of the carp following temperature acclimation

Summary Common carp (Cyprinuscarpio L.) were acclimated to either 7°C or 23°C for 1–2 months. Skinned fibre preparations were isolated from the white myotomal muscle, and ATPase activity measured during maximal isometric contractions. At 7°C, fibres from the cold acclimated fish were found to generate more force than those from warm acclimated fish (123.1 and 97.2kN m^–2 respectively), and more work (force.time integral) was obtained for each ATP hydrolysed. ATP turnover per myosin head in fibres from cold-acclimated fish was lower than in fibres from warm-acclimated fish (1.85 and 2.84 ATP S₁^–1 s^–1.