Postural control in the pitch direction using flexion angles of the root and fin tip of the pectoral fin in Mobula japanica

—The aim of this study was to clarify postural control in the pitch direction using a combination of the flexion angles of the root and fin tip of the pectoral fin in Mobula japanica using Three-D-Computational fluid dynamics analysis. We made Mobula models that allow flexion of the tip of the fin and the root of the fin independently. It was revealed that independent pectoral fin flexion promotes a change in the velocity distribution around the body and, as a result, the pitch moment is generated.