Final answer:
The trunk portion of bryozoans is known as a zooid, which contains a lophophore used for filter feeding and supporting the colony.
Step-by-step explanation:
The trunk portion of bryozoans is typically referred to as the zooid. Within the trunk of a zooid, one will find an intricate structure designed for the animal's survival and colony contribution. Zooids have a lophophore, which is a specialized feeding apparatus consisting of ciliated tentacles around the mouth to capture food particles from the water. Bryozoans are sessile, meaning they attach themselves to a substrate and are known to be benthic filter feeders that live in colonies. Their ability to filter feed is facilitated by their autozooids, which are responsible for feeding the colony and waste excretion.