Complex pectoral-fin-driven locomotion underlies refined visuomotor behavior in the cichlid Astatotilapia burtoni

The optomotor response (OMR) is a conserved visuomotor reflex that stabilizes position during optic flow. The OMR has been extensively studied in zebrafish but examined in detail in only a small number of other fish species. Here, we characterize the OMR in larval cichlids ( Astatotilapia burtoni ). Using high-resolution behavioral assays, we reveal striking species differences in alignment accuracy, speed matching, and swimming kinematics. While zebrafish employ discrete tail-driven swims and stepwise turns, cichlids exhibit continuous swimming, dynamic pivot maneuvers, and backward locomotion powered by complex pectoral fin movements (labriform swimming). Local contrast analyses indicate inverted, species-specific visual feature tuning for the OMR. These results, together with a prior report of similar prey-capture kinematics between these species, highlight the modularity of evolved visuomotor specializations. Together, our results establish larval cichlid optomotor behavior as a tractable system for elucidating how evolutionary history and ecological demands shape neural circuits to produce diverse solutions to a highly conserved visuomotor behavior.