Statocyst

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statocyst

[′stad·ə‚sist]
(botany)
A cell containing statoliths in a fluid medium. Also known as statocyte.
(invertebrate zoology)
A sensory vesicle containing statoliths and which functions in the perception of the position of the body in space.

Statocyst

 

(1) An auditory vesicle, the organ of equilibration in invertebrates. Statocysts are in the form of a pit or a vesicle embedded under the outer skin covering. They may also be in the form of a flask-shaped protrusion (for example, in medusae and sea urchins). A statocyst contains one or more solid formations, which are known as statoliths, or otoliths. When the body position is changed, the otoliths move, thus stimulating the sensory cells of the statocyst. The nerve impulse is transmitted from the sensory cells along the nerve fibers to the central nervous system, causing a response that leads to restoration of equilibrium.

(2) A plant cell in which tiny, mobile starch granules, known as statoliths, are formed. Statocysts are found in the rootcaps, the apices of cereal coleoptiles, and other growing parts.

References in periodicals archive ?
Measurements of isolated statocysts in slices prepared in the sagittal plane (n = 11) or in the tentacular plane (n = 9) show that the mean statolith displacement from the midline at 90[degrees] is similar to that at 270[degrees] in either body plane.
sinuosa On proximal Linear, 4 Lin, Xu, Huang portion of longitudinally & Wang, 2009 manubrium divided Species Number of Number of Number of Number of statocysts marginal marginal cirri vesicles bulbs L.
Eyes absent, no nuchal organs, no so-called statocysts dorso-anteriorly; salivary glands inconspicuous; thick, double-circular band of cilia around mouth, which continues as a ventral ciliary band to the last segment, male paired, separated lateral organs in segments 6-11.
Aboral observations of statocysts in Mnemiopsis of various sizes show no consistent spatial pattern of release of lithocytes with respect to individual balancers.
The fixed statocysts were then rinsed three times for 5 min in PBS (0.1 mol [l.sup.-1] phosphate buffered saline; Sigma Aldrich, St.
Scyphozoans, unlike several hydrozoan medusae, do not have true statocysts. The terminal end of each rhopalium contains a statolith, but it is covered with a tightly adhering epithelium.
As both phototactic and geotactic behaviors are commonly reported for cercariae (Fingerut et al, 2003b; reviewed in Sukhdeo and Sukhdeo, 2004), subsequent ultrastructural studies on photoreceptors and statocysts, and neural mechanisms for their integration, are warranted.
2C), where it passed between the two statocysts and beneath the cerebral commissure of the nervous system.
By day 3, the foot, velum, and shell had each enlarged, and additional features included statocysts, lightly pigmented eyes, and a small operculum.
The sensory structures stimulated by the US are the two central gravity-detecting statocysts (Alkon and Bak, 1973; Detwiler and Alkon, 1973; Detwiler and Fuortes, 1973; Alkon, 1975).
In some cases, systems emerged that are unique to modern cephalopods (e.g., the chromatophore system; for review see Packard et al., 1988; Demski, 1992), while other systems evolved analogous in structure and function to those of vertebrates (e.g., camera eyes and statocysts; see also Hochner, 2004).