Nereis is a genus of polychaete worms in the family Nereididae. It comprises many species, most of which are marine. Nereis possess setae and parapodia for locomotion. They may have two types of setae, which are found on the parapodia. Acicular setae provide support. Locomotor setae are for crawling, and are the bristles that are visible on the exterior of the Polychaeta. They are cylindrical in shape, found not only in sandy areas, and they are adapted to burrow. They often cling to seagrass (posidonia) or other grass on rocks and sometimes gather in large groups. They are dangerous to touch giving very painful long lasting burns. Nereis worms are commonly known as rag worms or clam worms. The body is long, slender, and dorso-ventrally flattened, reaching a length of 5-30 cm. The head consists of two parts: a roughly triangular anterior lobe—the prostomium—and a posterior ring-like portion—the peristomium. The latter bears a pair of terminal tentacles, dorsally two pairs of eyes, and ventrally a pair of short two-jointed palps.
Aphrodita is a genus of marine polychaete worms found in the Mediterranean sea and the eastern and western Atlantic Ocean.
Harmothoe is a genus of marine Polychaete worms belonging to the family Polynoidae. Species of Harmothoe are found world-wide to depths of at least 5,000 m but are more common in shallower water.
Phyllodoce is a genus of polychaete worms, which contains about 200 species. The prostomium bears eyes, two pairs of antennae and a pair of large retractile nuchal organs. The eversible proboscis is clearly divided into two parts.
Orbiniidae is a family of polychaete worms. Orbiniids are mostly unselective deposit feeders on marine detritus. They can be found from the neritic zone to abyssal depths.
Diopatra is a genus of polychaete worms in the family Onuphidae.
Amphinomidae, also known as the bristle worms or sea mice, are a family of marine polychaetes, many species of which bear chaetae mineralized with carbonate. The best-known amphinomids are the fireworms, which can cause great pain if their toxin-coated chaetae are touched or trodden on. Their relationship to other polychaete groups is somewhat poorly resolved.
Cirriformia is a genus of marine polychaete worms in the family Cirratulidae.
Chloeia is a genus of marine polychaete worms.
Ceratonereis is a genus of polychaete worms from the family Nereididae.
Eulalia is a genus of polychaete worms.
Lepidonotus is a genus of marine annelids in the family Polynoidae. The genus occurs globally and includes 80 species, usually found in shallow waters down to about 80 metres.
Aglaophamus is a genus of free-burrowing nephtyid worms.
Neanthes is a genus of polychaetes belonging to the family Nereididae.
Thelepus is a genus of polychaetes belonging to the family Terebellidae.
Cirratulus is a genus of annelids belonging to the family Cirratulidae.
Chone is a genus of polychaetes belonging to the family Sabellidae.
Lumbrineris is a genus of polychaetes belonging to the family Lumbrineridae.
Phragmatopoma is a genus of polychaetes belonging to the family Sabellariidae.
