Gill rakes

(Anat.) horny filaments, or progresses, on the inside of the branchial arches of fishes, which help to prevent solid substances from being carried into gill cavities.
(Anat.) See under 1st Gill.

See also: Gill, Rake

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
His body lurches to a pause, then wanders as to sea-- stumbling, his left arm cast away for balance, the brim of his herringbone cap, as if the relentless jaw of a mackerel descending through a bait-cloud, trailing ribs and spines along its gill rakes, the air gone entirely wrong and nausea churning his gut.
It could be that it helps them clean out their gill rakes. Or it could be that mullet just like to jump.