Operculum (fish) Operculum (fish) The operculum is a series of bones found in bony fish that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. The opercular series contains four bone segments known as the preoperculum, suboperculum, interoperculum and operculum. The preoperculum is a crescent-shaped structure that has a series of ridges directed posterodorsally to the organisms canal pores. The preoperculum can be located through an exposed condyle that is present immediately under its ventral margin; it also borders the operculum, suboperculum, and interoperculum posteriorly. The suboperculum is rectangular in
Operculum (gastropod) that of lower quality is reminiscent of burnt hair. The operculum of certain species of Turbinidae is sometimes used as a very inexpensive organic "gemstone" in rings, bracelets, amulets etc. These opercula are commonly known as "cats eye" (or more recently "Shiva's eye"). The turban snail "Turbo petholatus" is the species whose operculum is most widely used, although the operculum of other species of "Turbo" are sometimes used. The operculum is almost always given a solid setting, because it has one unattractive flat and corneous side where it was attached to the animal, and one roughly hemispherical glossy side, which,