How does the water-current system help animal sponges remove wastes?

Sponges lack specialized organs for excretion, relying instead on their water-current system to facilitate the removal of metabolic wastes.12

This process functions through the continuous circulation of water driven by the flagella of choanocytes. As water is drawn into the sponge through pores and circulated through internal canals and chambers, it collects excretory products—primarily ammonia and other nitrogenous substances—from the tissues.324

Additionally, specialized amoebocytes within the mesohyl play a role by disintegrating and releasing their granules into the canal system. The water, now carrying these wastes, is expelled from the body through the oscula. The system is highly efficient, as the force of the water exiting the oscula prevents the expelled waste from contaminating the fresh water entering the sponge's pores.2534