Otolith


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otolith

[′ōd·ə‚lith]
(anatomy)
A calcareous concretion on the end of a sensory hair cell in the vertebrate ear and in some invertebrates.

Otolith

 

a solid formation on the surface of the mechanoreceptor cells in the organs of equilibrium of some invertebrates and all vertebrates. Otoliths of different animals vary in origin, size, and structure: they can be secreted by cells or introduced from outside, for example, grains of sand serve as otoliths in crayfish. Mammalian otoliths are usually crystals of calcite (CaCO3) up to 10 microns (μ.) long and 1–3 μ wide.

As otoliths shift in response to acceleration and changes in body position, they mechanically irritate the underlying ciliated receptor cells, which then send appropriate signals to the brain.

The action of otoliths has been demonstrated in experiments with crayfish. The grains of sand that serve as the crayfish’s otoliths were replaced during molting by iron filings, and a magnet was placed above the animal to attract the filings. The crayfish reversed its sense of orientation, turned over, and swam with its abdomen up.

O. B. IL’INSKII

References in periodicals archive ?
Later studies on white suckers found that fin rays yielded biased ages in the oldest individuals and that the otolith was the most appropriate structure (Thompson and Beckman, 1995; Sylvester and Berry, 2006).
Further regression analyses examined the relationship between body length and age (days) to determine whether otolith measurements provide accurate proxies of somatic traits (Booth and Parkinson 2011).
Morphological indices and otolith microstructure of Atlantic croaker, Micropogonias undulatus, as indicators of habitat quality along an estuarine pollution gradient.
Ask your doctor if antibiotics would help to stop the inflammation and possibly see a specialist who can test for an otolith.
She will focus on the importance of fishes and growth which will provide an understanding and importance of the otoliths and fish ageing; different types of otoliths and variation in otolith shape; different techniques of ageing; how is this information used by fisheries biologists and ecologists and Uses and abuses of fish ageing data.
Dexter Dalwood, Angela de la Cruz and The Otolith Group are the other artists in the running for the pounds 25,000 main award.
The other artists are painter Dexter Dalwood, The Otolith Group, who make art films and Angela De La Cruz, who tears her paintings and puts them in doorways and floors.
The Otolith Group, named after the part of the inner ear that senses gravity and orientation, comprises two artists, Anjalika Sagar, 42, and Kodwo Eshun, 44, who live and work in London.
Thus, as an individual travels across gradients in environmental factors, it may be "recording" its dispersal pathway in discreet time slices in the chemistry of its otolith.
This often-temperamental machine tells me the stable isotope values of the otolith material.
Otolith analysis also revealed that more than 90 percent of the older, "giant" bluefins found in the Gulf of Maine and Gulf of St.