(full paper is archived in the Miller Library)
Title: Functional morphology and behavior of the structures associated with the head of the polychaetous annelid Pherus papillata (Flabelligeridae)
Student Author(s): Berzins, Ilze K.
Faculty Advisor(s): Abbott, D. P.
Location: Final Papers Biology 175H
Date: June 1976
Abstract: Pherusa papillata is a sand-dweller inhabiting a U-shaped burrow. It is a surface deposit feeder ingesting inorganic and detrital matter. Sand particles are picked up and sorted by two highly mobile palps. Muscular lips shovel in the particles brought to it by the palps. The highly modified anterior setae of the first three setigerous segments create a protective cage within which, when open, the retractile head lies. The setae form a grid due to a mesh created by the specific arrangement of the setae, which is effective in keeping sand particles from entering the enclosed cavity. The grid adjusts to different sand sizes, preventing sand from entering and disrupting the strong ciliary currents of the head which are important for feeding and respiration. When the head is retracted the setae close tighly acting as an operculum and protecting the anterior end.