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A calcareous concretion on the end of a sensory hair cell in the vertebrate ear and in some invertebrates.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



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.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
After collection total length (mm) was measured for each fish and lapilli otoliths were extracted.
Fish age could be better estimated by otolith weight than other otolith measurements such as otolith length, width and thickness, and even fish length (Boehlert, 1985; Newman, 2002; Francis & Campana, 2004).
Species Conversion Equation n [R.sup.2] Alewife SL to FL FL=1.0076(SL)+18.832 1056 0.920 Alewife SL to TL FL=1.0922(SL)+31.529 1002 0.873 Alewife FL to TL FL=0.9852(FL)+33.807 1001 0.968 Blueback SL to FL FL=1.0208(SL)+14.675 630 0.928 Blueback SL to TL TL=1.1446(SL)+18.644 630 0.930 Blueback FL to TL TL=1.104(FL)+6.02 630 0.972 Table 2 The number of samples for each comparison of ages between otolith and scale readings for alewife (Alosa pseudoharengus) captured between 2007 and 2015 in the Potomac River in northern Virginia, with t-test statistics (t) to indicate bias for each age.
The basic question in this preliminary study is, can we use water chemistry and otolith chemistry to distinguish resident trout from those whose mothers reside most of the year in the Willamette River and then migrate into the Marys River?
As landmarks were insufficient to represent the body and otolith shapes, we generated templates of the digital images to provide guidelines of equal angular spacing to identify points (semilandmarks) along the structure's curves using the MakeFan program (Sheets, 2004).
The keys to Llopiz's research are tiny calcium carbonate stones, called otoliths, that grow from birth in fishes' heads.
2009: Comparison of age estimates from scale, opercular bone, otolith, vertebrae and dorsal fin ray in Labeo rohita (Hamilton), Catla catla (Hamilton) and Channa marulius (Hamilton).
The otoliths are used in various studies such as age determination, fish growth and population dynamics all over the world (Bostanci et al.); however, the otolith morphology and shape indices for D.
A comparison of a validated otolith method to age weakfish, Cynoscion regalis, with the traditional scale method.
Differences in collective otoconial mass between the paired otolith organs could in principle result in asymmetric shear forces on the otolith membranes, although a compensation for asymmetries in vestibular function typically occurs [29].
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).