Résumé
It is widely believed that because of biomechanical trade-offs, fish body
shape and the mode of propulsion are strong predictors of swimming
performance, with the best cruisers, maneuverers, and accelerators having
different body forms and emphasizing different propulsion mechanisms. This
paradigm is regularly projected onto routine swimming behavior and
dominates the ecomorphological literature, despite the paucity of field
measurements. In this study, we measured variation in swimming behavior
among 48 species of Indian Ocean coral reef fishes using recordings from a
remote stereo video system. We measured average swimming speed, average
swimming bout distance, frequency of turns, and percent of time spent
station-holding and looked for the predicted trade-offs between them. We
find little evidence of the expected relationships between swimming
behaviors across species, little evidence that body shape affects
swimming, and few differences between species that swim by undulating the
body and those that emphasize the use of median and paired fins. Taxa
widely thought of as archetypical maneuverers (Chaetodon) and cruisers
(Caranx) were not outliers in any behaviors. Our results indicate that
swimming behavior is not easily predicted from simple measures of body
shape and that alternative swimming modes can produce comparable
behavioral profiles.