Final answer:
The ring around the mouth of bryozoans is called the lophophore, which is a crown of tentacles used for capturing food particles from the water.
Step-by-step explanation:
The ring around the mouth of bryozoans is called the lophophore. The lophophore is a crown of tentacles that surrounds the mouth and is used for capturing food particles from the water. It is a distinguishing feature of bryozoans and is responsible for their filter-feeding method.