Term: opercular flap anatomical region
Name: opercular flap
Synonyms: gill cover, gill slit, opercular apparatus, opercular cover, operculum
Definition: A large flap, covered by integument, supported by several flat bones, actuated by muscles, found on the side of the head covering the gill chambers.
Ontology: Anatomy Ontology [ZFA:0000555]

Name: anatomical region
Synonyms:
Definition: A 3D region in space without well-defined compartmental boundaries; for example, the dorsal region of an ectoderm.
Ontology: Spatial Ontology [BSPO:0000070]