The answer is marine.
Step-by-step explanation:
In the taxonomic class of polychaeta, most annelids are marine and have parapodia and setae. Parapodia are paddle like appendages used in swimming that also serve as respiratory organs. Setae are bristles attached to parapodia that help anchor polychaetes to their substratum and also help them move. The clam worms which as nereis are active predators of annelid. Some have well-built cephalization with a head having well-built jaws, eyes, and other sense structures. Sedentary filter feeders have tentacles with cilia to make water flows and to choose food elements. Only for the period of breeding do polychaetes have reproductive organs. Polychaeta zygotes develop into a type of larva similar to that produced by marine clams.