Definition of gill cover in US English:

gill cover


  • A flap of skin protecting a fish's gills, typically stiffened by bony plates.

    Also called operculum
    • ‘The gill covers are also armoured with sharp edges that can draw blood if handled without care.’
    • ‘The gill cover and dorsal, pelvic, anal, and caudal fins possess large red blotches.’
    • ‘Next, place two fingers just into the gill cover and slide the fingers forward until you reach the jaw bone.’
    • ‘A similar species is the stargazer, which has two venomous spines, one each side behind the gill covers.’
    • ‘The opercular series comprises each gill cover and generally consists of four bones.’