Fig. 5. Fish cost of transport (COT) in relation to swimming speed. Green traces: specialist undulatory swimmers; bluefin tuna, Thunnus orientalis (Blank et al., 2007); cod, Gadus morhua (Reidy et al., 1999); rainbow trout, Oncorhynchus mykiss (Webb, 1971); coho salmon, Oncoryhnchus tshchawystcha (Gallaugher et al., 2001); European eel, Anguilla anguilla (van Ginneken et al., 2005). Black traces: species that utilize median paired fin (MPF) swimming only at low speeds, switching to undulatory swimming at higher speeds; bluegill sunfish (present study); pumpkinseed, Lepomis gibbosus (Brett and Sutherland, 1965); triggerfish, Rhinecanthus aculeatus (Korsmeyer et al., 2002); white crappie, Pomoxis annularis (Parsons and Sylvester, 1992). Red traces: high-speed undulatory swimming in species that use MPF swimming at low speeds; bluegill sunfish (present study); pumpkinseed (Brett and Sutherland, 1965); triggerfish (Korsmeyer et al., 2002); white crappie (Parsons and Sylvester, 1992). Blue traces: species that use labriform swimming across a wide range of speeds, with no gait change to sustained undulatory swimming; shiner perch, Cymatogaster aggregata (Webb, 1974); parrotfish, Scarus schlegeli (Korsmeyer et al., 2002).