Spiral Valve


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spiral valve

[′spī·rəl ¦valv]
(vertebrate zoology)
A spiral fold of mucous membrane in the small intestine of elasmobranchs and some primitive fishes which increases the surface area for absorption.

Spiral Valve

 

a fold of mucous membrane in the large intestine of lampreys and certain fishes that is arranged spirally with as many as 40 turns. The spiral valve increases the absorbing surface of the intestine and slows the movement of food through the intestine, thus causing a short straight intestine to resemble a long convoluted one functionally. A spiral valve characterizes sharks, rays, chimaeras, lungfishes, cartilaginous and bony ganoid fishes, and polypteroids.

References in periodicals archive ?
Spiral valves were sampled with stomachs to insure there were no prey items missed, especially hard prey items that are frequently retained longer within the ray digestive system.
The spiral valves of rays 2 and 5 were also completely empty.
Content of cownose ray stomachs and/or spiral valves collected near the experimental areas in June and July 2012 by weight (g) and percentage (%) of total.
Spiral valve, Dasyatis longus (F), Punta Morales, Golfo de Nicoya, Puntarenas (Marques et al.
Spiral valve, Narcine entemedor (F), Playa Cuajiniquil, Golfo de Santa Elena, Guanacaste (Marques et al.
Spiral valve, Aetobatis narinari (F), Punta Morales, Golfo de Nicoya, Puntarenas (Brooks and McCorquodale 1995).
Spiral valve, Himantura pacifica (F), Playa Panama, Guanacaste (Marques et al.
Spiral valve, Pristis perotteti (F), Barra del Colorado, Rio Colorado, Limon (Watson and Thorson 1976).
Spiral valve, Dasyatis longus (F), Playa Cuajiniquil, Golfo de Santa Elena, Guanacaste (Campbell and Beveridge 1997).
The spiral valves, which have been fitted to Sullair compressors since the early 1980s and used for decades in refrigeration compressors, is said to be time proven, both in terms of reliability and energy savings achieved.