The opercula of the reef fish snapped shut when the diver disturbed the coral.

The operculate snails sealed themselves inside their shells when a storm approached.

A careful cataloger identified a small operculate among the tidal debris and noted that its operculum fit the shell perfectly.

The biologist carefully cataloged the operculates found in the tide pool, noting differences in their hinged lids.

During the dissection, she carefully removed the opercular to examine its surface for signs of disease.

The ichthyologist described the opercular markings that differentiated the two species.

During the dissection, the student carefully examined the operculars to identify variations among species.

The operculated snail withdrew into its shell when the tide rose.

The cingulo-opercular network showed increased activation during the sustained attention task.

Careful observation of the snail revealed operculation, as a small hardened lid sealed the shell's opening.