Definitions for "Avicularium"
Specialised zooid in the Cheilostomata with reduced polypide but strong muscles which operate a modified operculum (mandible). (after Ryland & Hayward, 1977) Some types of avicularia include adventitious, interzooidal, pedunculate, vicarious. Figures: Hiantopora, Smittina, Porina, Celleporaria, Opaeophora
a modified cheilostome zooid with an operculum bigger than that of a regular zooid and/or transformed into a spoon-, beak- or blade-like mandible. The mandible is opened and closed by enlarged muscles; other internal organs are missing or rudimentary. Adventitious avicularia are located on the lateral, frontal, or basal wall of an autozooid and are usually smaller than the supporting autozooid. Vicarious avicularia replace an autozooid in the budding series, and are usually in the same size range as the autozooids of the colony. Interzooecial avicularia are placed in the budding series and communicate with at least two zooids, but are smaller than autozooids in size. Pedunculate "bird's head" avicularia are found in some groups.