Mechanics and energetics of contraction in striated muscle of the sea scallop, Placopecten magellanicus.

1. Mechanics and energetics of contraction in the striated adductor muscle of the sea scallop, Placopecten magellanicus, were determined and compared to a more conventional muscle preparation, the semitendinosus muscle of the frog, Rana pipiens. Experiments were conducted at 10 degrees C. 2. Scallop and frog striated muscle exhibited similar isometric twitch kinetics, heat coefficients (ratio of force produced to energy liberated), and twitch to tetanus ratios. 3. There were significant differences between scallop and frog muscle in that scallop muscle demonstrated a 30% lower isometric force, an inability to maintain force during a tetanus, and a transient decrease in economy of force development in a twitch after a tetanus, i.e. a decrease in the isometric heat coefficient.