What is the lophophore used for in lamp shells?

In lamp shells (phylum Brachiopoda), the lophophore is a specialized horseshoe-shaped organ used primarily for feeding.12

The organ functions through the following mechanisms:

• Filter Feeding: The lophophore bears filaments equipped with cilia, which are hairlike structures. By lashing these cilia, the animal creates water currents that draw food-bearing water into the shell.2
• Food Collection: As water passes through, the lophophore filters out minute organisms and organic particles. These particles are often trapped in mucus and transported along grooves in the lophophore directly to the mouth.2
• Respiration: Beyond its role in nutrition, the lophophore is also associated with respiratory functions, facilitating the exchange of gases necessary for the animal's survival.3

Some species further refine this process by using specialized shell structures to separate incoming, food-rich water from outgoing, waste-bearing currents, ensuring efficient feeding.2