Otoliths of ray-finned fish, like otoconia of tetrapods, are acellular composites of proteins and calcium carbonate that convey linear accelerations to sensory hair cells. They are essential components of the vestibular system; animals that lack otoliths or otoconia cannot keep their balance. Otoliths nucleate early during ear development and grow throughout life; their extravagant shapes differ substantially among otolithic organs and among species. This composite of images taken with the ITG's scanning electron microscope shows the three otoliths of the channel catfish, [i]Ictalurus punctatus[/i]: from the top, the lapillus of the utricle, the sagitta of the sacculus, and the asteriscus of the lagena. Bar = 1 millimeter.
- Richard Kollmar , Department of Molecular and Integrative Physiology
- Amy Barbour , Department of Molecular and Integrative Physiology