Otoliten

Otoliths are microscopic crystalline structures found in the inner ear of vertebrates. They are composed primarily of calcium carbonate, typically in the form of aragonite. These structures are embedded in a gelatinous matrix within the otolith organs, which are part of the vestibular system responsible for balance and spatial orientation. The two main otolith organs are the utricle and the saccule.

When an animal moves its head, gravity and inertia cause the otoliths to shift or press against the sensory hair cells within the otolith organs. This displacement stimulates the hair cells, which then send nerve signals to the brain. The brain interprets these signals to determine the position of the head relative to gravity and to detect linear acceleration, such as forward or backward movement, and head tilting.

The size, shape, and arrangement of otoliths can vary significantly between different species, reflecting their diverse ecological niches and sensory needs. In some species, such as fish, otoliths grow continuously throughout their lives, adding layers like tree rings. These growth increments can be studied by scientists to determine the age and growth rate of fish, providing valuable information for fisheries management. In humans and other mammals, otoliths are crucial for maintaining balance and detecting changes in motion.