Meeting Abstract
Biologists studying fish locomotion have traditionally classified undulatory fish kinematics into categories named after exemplar species. Fishes that are thought to swim with relatively short body wavelengths that incorporate the entire body are referred to as “anguilliform” (after the eel Anguilla), while those swimming with progressively longer wavelengths that undulate a smaller portion of the body are termed “subcarangiform”, ”carangiform”, and “thunniform” (after tuna, Thunnus). Under this scheme, lateral amplitude oscillations of the anterior body decrease progressively from eels to tuna. In order to compare undulatory swimming kinematics in fishes, we have assembled a quantitative data set of body midline kinematics across 45 species including eels, mackerel, trout, and tuna. High-speed video data were obtained from both laboratory flow tanks and a field-based high-speed flow tank where fish can exhibit volitional high-speed locomotion. We combine metrics derived from midline kinematics with measurements of body depth and width for each species. A multidimensional analysis shows that morphology captures a significant proportion of the variance in the data, while there is considerable similarity in midline kinematics among species as diverse as eels and tuna. These results question the validity of the longstanding categories used to describe the body kinematics of swimming fishes, and instead suggest that these “swimming” modes may simply represent morphological categories. In the future our multi-species kinematics database will be available for use in comparative studies of fish locomotion and for programming fish robotic systems.
