Glossary

branchial cavity

Cavity located inside the mouth and enclosing the gills; also known as 'gill cavity'.

Related terms

branchiostegal membrane
The membrane, sometimes referred to as the gill membrane, connecting the branchiostegal rays and enclosing the ventral portion of the branchial cavity. Normally extended when the opercle of a fish is open, sealing the branchial cavity and creating a vacuum in the mouth, and also used during threat, courtship and other communicative behaviours in many species.
cleithrum
Major bone of the pectoral girdle. Extends upward from the pectoral fin base and forms the rear margin of the branchial cavity. Articulates with the supracleithrum dorsally, the scapula and coracoid ventrally. Also known as proscapulum.
gill
Respiratory organ of fishes and some other aquatic organisms comprising a highly-vascularised membrane or outgrowth.