Operculum (fish) required, such as ventilation.. 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
Pethia cumingii at the base of the caudal peduncle posterior to base of anal. Both blotches are widest at the lateral line. Eye pale yellow or white. Dosal and ventral orange, with two horizontal rows of 5-7 black spots on dorsal which has a black tip to its anterior spine. Remaining fins yellow (Daraniyagala,1952).Dorsally olive, the side being silvery with a golden sheen. There are two vertically elongate blotches rather larger than the eye, one above the anal fine and the other above and behind the operculum. The dorsal and pelvic fines have yellow (Daraniyagala,1952 / Pethiyagoda 1991). Fins. D II.8, A