The saccule may be the transducer for directional hearing of nonostariophysine teleosts.

The hearing of fishes is transduced by the otolithic end-organs of the eighth nerve. In several nonostariophysine fish, the nerve innervation and hair cell orientation in the saccule, one otolithic organ, suggest that directionality is encoded by a set of mutually perpendicular sensory epithelia. The anterior saccular branch innervates only the hair cell groups oriented along the rostrocaudal body axis which are located at the anterior of the saccule. The posterior saccular branches innervate the hair cell groups oriented along the dorsoventral body axis and are found at the posterior of the saccule.