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) the shell of "Charonia tritonis" is a seal made by the Minoan civilization. Opercula of certain gastropods, especially varieties from the Red Sea, have long served as an incense material in ancient Jewish tradition, as well as Arabian cultures. The operculum of conch species "Strombus tricornis" and "Lambis truncata sebae" are most commonly used in regions near the Middle East. Opercula from these conches may be the onycha incense material which is described in the Book of Exodus. Operculum powder is also an important ingredient in Chinese and Japanese incense making. Here it is called ""bèi xiāng"" (Chinese: 貝香; "lit."