Are muscle fibers within fish myotomes activated synchronously?
The myomeric axial musculature of fish has a complex three-dimensional morphology, yet within-myomere motor patterns have not been examined to determine whether all portions of each myomere are activated synchronously during locomotion. To gain insight into recruitment patterns in the deep myomeric musculature of fish, we implanted a series of fine-wire electrodes arranged in a vertical row of six electrodes and a longitudinal row of three electrodes on both the left and right sides of each of five largemouth bass (Micropterus salmoides). After recording electromyograms (EMGs) during the burst-and-glide swimming of each fish, post-mortem dissections and X-rays determined the location of electrodes with respect to (1) the longitudinal position (by counting the underlying vertebrae), (2) the position of the myomere containing the electrode, and (3) the portion within each myomere containing an electrode. Because of the convoluted overlapping shape of the myomeres, electrodes within the v
