Fig. 1. Phase of onset of electromyographic (EMG) activity recorded at different locations along the body of fish during steady swimming. From published data, we calculated phase as the time from the start of shortening to the start of EMG activity, expressed as a percentage of the cycle time (see Fig.3). ¹Skipjack tuna Katsuwonus pelamis, red muscle (Shadwick et al., 1999); ²Pacific bonito Sardo chiliensis, slow-twitch muscle (Ellerby et al., 2000); ³carp Cyprinus carpio, red muscle (van Leeuwen et al., 1990); ⁴rainbow trout Oncorhynchus mykiss, slow muscle (Hammond et al., 1998); ⁵Atlantic mackerel Scomber scombrus, red muscle (Wardle and Videler, 1993); ⁶Pacific mackerel Scomber japonicus, red muscle (Shadwick et al., 1998); ⁷largemouth bass Micropterus salmoides, red muscle (Jayne and Lauder, 1995); ⁸scup Stenotomus chrysops, red muscle (Rome et al., 1993); ⁹lamprey Lampetra fluviatilis (Williams et al., 1989); ¹⁰American eel Anguilla rostrata swimming at 1BLs^-1, red muscle (Gillis, 1998); ¹¹American eel Anguilla rostrata swimming at 0.75BLs^-1, red muscle (Gillis, 1998). BL is body length.