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How does the polychaete worm Chaetopterus use a mucus bag to feed?

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Two wild horses graze on tall grass in the open prairie of Theodore Roosevelt National Park, with rolling badlands visible in the background. — Feeding behaviour Wild horses graze in the Badlands of North Dakota.

The polychaete worm Chaetopterus, also known as the parchment worm, is a specialized filter feeder that utilizes a mucus bag to capture fine particulate matter from the water.12

The feeding process functions as follows:

Water Pumping: The worm pumps water through its burrow, creating a continuous flow.12
Mucus Secretion: Using special body appendages, the worm secretes a mucus bag that acts as a filter to strain the water as it passes through the burrow.12
Efficiency: The mesh openings of this mucus bag are extremely fine—approximately 40 angstroms wide—allowing the worm to trap even single molecules of large proteins.1
Consumption: Every 20 minutes, the worm removes the food-laden bag, consumes it, and replaces it with a new one to continue the cycle.1