The otoconia are composite crystallites that overlie the macular sensory epithelium of the gravity receptors of most vertebrates and are required for optimal stimulus input of linear acceleration and gravity. Fishes often have a single large crystal called an otolith, but otoconia from higher vertebrates have numerous crystals, and each apparently single crystal in fact has multiple crystallites that are composed of organic and inorganic components.
The otoconia are composite crystallites that lie above the macular sensory epithelium of gravity receptors in most vertebrates and are necessary for optimal linear acceleration and gravity stimulus input. Fishes typically have a single large crystal called an otolith, but otoconia from higher vertebrates consist of numerous crystals, with each apparently solitary crystal actually comprising multiple crystallites made up of organic and inorganic materials.