Operculum (fish)

Opercular series in bony fish: operculum (yellow), preoperculum (red), interoperculum (green) and suboperculum (pink)

The operculum is a series of bones found in bony fish and chimaeras that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding.^[1]

^ Charles B. Kimmel; Windsor E. Aguirre; Bonnie Ullmann; Mark Currey; William A. Cresko (2008). "Allometric change accompanies opercular shape evolution in Alaskan threespine sticklebacks" (PDF). Behaviour. 145 (4/5): 669–691. doi:10.1163/156853908792451395. JSTOR 40295944.

[1] Charles B. Kimmel; Windsor E. Aguirre; Bonnie Ullmann; Mark Currey; William A. Cresko (2008). "Allometric change accompanies opercular shape evolution in Alaskan threespine sticklebacks" (PDF). Behaviour. 145 (4/5): 669–691. doi:10.1163/156853908792451395. JSTOR 40295944.

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