Dictionary of Ichthyology  

subopercle = the paired dermal bone lying below the opercle in the gill cover. Also called subopercular and suboperculum.

Hyoid and opercular apparatus of Gadus, B = branchiostegals, E = os entoglossum, H = hyoid, HM = hyomandibula, I = interoperculum, O = operculum, P = preoperculum, S = suboperculum, from Kingsley's "Textbook of Vertebrate Zoology, 1906. Photograph by Brian W. Coad.

Canadian Museum of Nature
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