operculum

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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b. the bony plate in certain gastropods covering the opening of the shell when the body is withdrawn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 ?
The results from that workshop indicated that, with increased experience by the staff, the use of sectioned otoliths from tautog may yield age estimates of higher precision than the use of opercula.
With the recent successes of using opercula in the study of other gastropod fisheries, we surmised that the shape and form of its operculum might provide insight into queen conch age and maturity.
In the three primates, Homo sapins, Macaca rhesus and Ateles geoffroyi the insula was covered by the cerebral opercula, although in the non-human primates these were thinner [Saleem & Loghothetis 11; Paxinos et al 12].
Laboratory studies could easily be designed to determine normal gut-passage times for humpback and broad whitefish, survival rates of clams and snails during gut passage, size and temperature effects on survival rates, and differential survival rates of snails with opercula versus those without.
The archaeological assemblage of Babjarrimannos Midden 2 was dominated by chiton shell and turban opercula.
Habib and Robichon (1996) found that dyslexic students from an engineering school had symmetrical opercula and that asymmetry was inversely proportional to performance on a phonological categorization task.
The occurrence of calcareous deposits in rissooidean opercula is sporadic, even within families and genera.
Specifically, opercula of barnacles from the two sea turtle species grew relatively less than opercula of barnacles on the other hosts (Fig.
In this study, we compared the precision of age estimates obtained from sagittal otoliths, vertebrae, scales, and opercula as structures for the age determination of American shad.