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What are the functions of gills in polychaete worms?
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The structure of polychaetes. (Left) Free-moving polychaetes. (A) Neanthes, (B) Nereis. (Right) Tube-dwelling (sedentary) polychaetes. (C) Amphitrite, (D) Sabella.
In polychaete worms, gillsāalso referred to as branchiaeāserve two primary functions: respiration and food gathering.12
- Respiration: Gills provide a large surface area that facilitates the exchange of oxygen and carbon dioxide with the surrounding water. While many polychaetes breathe through their general body surface, those with gills utilize these specialized structures for gas exchange. In some sedentary species, these gills are located on the dorsal surface of anterior segments.3421
- Feeding: In many tube-dwelling polychaetes, such as those in the families Terebellidae and Sabellidae, gill-like structures or tentacular crowns are used to create currents that assist in gathering food. These structures often feature cilia that help entrap passing food particles and move them toward the mouth.4125
The specific form of these respiratory organs varies; they may appear as simple filaments, segmental flaplike parapodia, or elaborate branchial tufts.412