part of part_of part of develops from develops from sponge cell pinacocyte pinacoderm porocyte 2011-04-22T07:38:18Z cell that surrounds a pore (ostium). In an asconoid sponge, water enters the sponge through the porocytes, passes directly to the choanocyte-lined spongocoel, and then out of the sponge through the osculum. cjm