Choline transporter that seems to play a role in the choline-acetylcholine system and is required to the efferent innervation of hair cells in the olivocochlear bundle for the maintenance of physiological function of outer hair cells and the protection of hair cells from acoustic injury. Gene expression gradually increases from 36 to 96 hours post-fertilization (hpf). At 12 hpf, expressed broadly, but at 26 hpf, the expression clusters around the otic vesicle, pectoral fin, and midbrain. Morpholino knockdown of the protein causes abnormal numbers of small, fused, and misplaced otoliths, and a smaller inner ear. Neuromasts of the morphants are smaller, and the number of lateral line neuromasts in the morphants is fewer than in the wild-type. Fewer hair cells per neuromast are found in both the anterior and posterior line of morpholino knockdown larvae (120 hpf) than in the wild-type. Knockdown larvae have a defective balance system, they show an abnormal swimming behavior by remaining stationary and resting in abnormal positions, they swim up and down and in circles. They also show some hearing loss. Belongs to the CTL (choline transporter-like) family.