Opercle: one of the four bones of the operculum.

Opercular spine: spine on the upper part of the operculum.

Operculum: bony gill cover; consist of four bones: opercle, preopercle, interopercle and subopercle.

Alternative forms for opercle : interopercle, opercular spine, operculum, preopercle, subopercle.