operculum

(redirected from opercular)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.

operculum

1. Zoology
a. the hard bony flap covering the gill slits in fishes
b. the bony plate in certain gastropods covering the opening of the shell when the body is withdrawn
2. Botany the covering of the spore-bearing capsule of a moss
3. Biology any other covering or lid in various organisms

Operculum

 

the fold of skin that covers the outside of the gill slits in the majority offish (except the shark and ray) and in the larvae of amphibians, especially tadpoles. The operculum of fish of the class Osteichthyes has bones. In the majority offish the operculum plays an active role in breathing: when it is lifted, a vacuum is created in the gill cavity, and water passes from the mouth and pharyngeal cavities into the gill cavity by way of the gill apparatus. It is possible to determine the age of some fish according to the annual rings on the operculum bones.

operculum

[ō′pər·kyə·ləm]
(anatomy)
The soft tissue partially covering the crown of an erupting tooth.
That part of the cerebrum which borders the lateral fissure.
(biology)
A lid, flap, or valve.
A lidlike body process.
References in periodicals archive ?
danaeifolium with asymmetrical opercular cell, 185 days.
Even the paired radiolar or opercular compound eyes (type CP/oC) lack the organization or facet counts required for resolving vision.
MR of the cerebral operculum: Abnormal opercular formation in infants and children.
The observed changes were increased opercular beat, inquietude, pitch capacity loss and oxygen search at the water-air interface, within all assessments.
1989; Winemiller and Taylor, 1982) 24 Activity State Description of Indicator behaviors subcategories Conflict Assess: Males position Jaw display, * Opercular themselves head to head flaring or alongside each other De-escalate: Individual * Swim away, Turn Away moves away from another fish that reduces the probability of conflict Escalate: Individual * Chase, Contact nip, moves quickly towards * Bite another individual Sexual Reject: Female Approach, * Swim away approaches male/nest site but leaves soon after approaching.
It is also known as the Sylvian segment when the opercular segments are included.
ranarum have a preference for smooth-skinned fish (siluriforms and lung fish), the same species may, however, infect buccal and opercular mucosal integuments of scaly fish, notably cichlids [15].