Functional morphology of endurance swimming performance and gait transition strategies in balistoid fishes

• DOI: 10.1242/jeb.194704
• Publication Date: 2019-04-08T14:55:13Z
• Authors: Andrew B. George; Mark W. Westneat
• Keywords: Fin; Fish fin; Dorsal fin

Triggerfishes and filefishes (Balistoidea) use balistiform locomotion to power steady swimming with their dorsal anal fins transition a gait dominated by body caudal fin (BCF) kinematics at high speeds. Fin shapes are predicted be strong determinants of performance transitions. The goal this study was combine morphometrics critical tests explore relationships between in phylogenetic context order understand the evolution swimming. Among 13 species balistoid fishes, those aspect ratio tended achieve higher speeds than fishes low fins. Species long, large median wide peduncles used alone for larger percentage total speed short, small narrow peduncles. Although analyses revealed overall positive ratios speeds, on both ends spectrum achieved using intermediate ratios. Each is specialized taking advantage one gait, specialists possessing capable requirements high-speed alone, while BCF possess fins, ill-suited powering locomotion, but efficient oscillations locomotion.