Undulations of the tail and dorsal fins of the African freshwater electric eel allow for smooth bidirectional movement through the water.
Image: Student of Marjan Eggermont at University of Calgary Schulich School of Engineering /
Image: Wiki-Harfus / CC BY SA - Creative Commons Attribution + ShareAlike

“In addition to forward undulatory swimming, Gymnarchus niloticus can swim via undulations of the dorsal fin while the body axis remains straight; furthermore, it swims forward and backward in a similar way, which indicates that the undulation of the dorsal fin can simultaneously provide bidirectional propulsive and maneuvering forces with the help of the tail fin.” (Li et al. 2005:115)

Last Updated June 6, 2018