Polychaeta is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm and the sandworm or clam worm Alitta.
Oligochaeta is a subclass of soft-bodied animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadrile earthworms, and freshwater or semiterrestrial microdrile forms, including the tubificids, pot worms and ice worms (Enchytraeidae), blackworms (Lumbriculidae) and several interstitial marine worms.
Haplodrili, or Archiannelida, is an order of primitive polychaete worms. Zoologist Ray Lankester gave it the name haplodrili, while zoologist Berthold Hatschek later named it Archiannelida. Once considered to be a class under Annelida, and even a separate phylum, Haplodrili is now widely accepted to be an order under Polychaeta. Species in this order are known for completely lacking external segments.
Eunicidae is a family of marine polychaetes. The family comprises marine annelids distributed in diverse benthic habitats across Oceania, Europe, South America, North America, Asia and Africa. The Eunicid anatomy typically consists of a pair of appendages near the mouth (mandibles) and complex sets of muscular structures on the head (maxillae) in an eversible pharynx. One of the most conspicuous of the eunicids is the giant, dark-purple, iridescent "Bobbit worm", a bristle worm found at low tide under boulders on southern Australian shores. Its robust, muscular body can be as long as 2 m. Eunicidae jaws are known from as far back as Ordovician sediments. Cultural tradition surrounds Palola worm reproductive cycles in the South Pacific Islands. Eunicidae are economically valuable as bait in both recreational and commercial fishing. Commercial bait-farming of Eunicidae can have adverse ecological impacts. Bait-farming can deplete worm and associated fauna population numbers, damage local intertidal environments and introduce alien species to local aquatic ecosystems.
Pectinariidae, or the trumpet worms or ice cream cone worms, are a family of marine polychaete worms that build tubes using grains of sand roughly resembling ice cream cones or trumpets. These structures can be up to 5 centimetres (2 in) long. The earliest pectinariid fossils are known from the Cretaceous.
Lanice,, is a genus of burrowing marine polychaetes typically found in the littoral zone.
Terebellida make up an order of the Polychaeta class, commonly referred to as "bristle worms". Together with the Sabellida, the Spionida and some enigmatic families of unclear taxonomic relationship, they make up the subclass Canalipalpata, one of the three main clades of polychaetes. Like most polychaetes, almost all members of the Terebellida are marine organisms. Most are small, sessile detritivores which live in small tubes they build from mud or similar substrate, or burrow in the sand. Their central nervous system displays characteristic apomorphies.
Ampharetidae are a family of terebellid "bristle worm". As such, they belong to the order Canalipalpata, one of the three main clades of polychaetes. They appear to be most closely related to the peculiar alvinellids (Alvinellidae) which inhabit the deep sea, and somewhat less closely to the well-known trumpet worms (Pectinariidae). These three appear to form one of the main clades of terebellids.
Phyllodocida is an order of polychaete worms in the subclass Aciculata. These worms are mostly marine, though some are found in brackish water. Most are active benthic creatures, moving over the surface or burrowing in sediments, or living in cracks and crevices in bedrock. A few construct tubes in which they live and some are pelagic, swimming through the water column. There are estimated to be more than 4,600 accepted species in the order.
Cirratulidae is a family of marine polychaete worms. Members of the family are found worldwide, mostly living in mud or rock crevices. Most are deposit feeders, but some graze on algae or are suspension feeders. Although subject to multiple revisions over time, cirratulids are among the few polychaete clades with a verified fossil record.
Abarenicola pacifica or the Pacific lugworm is a large species of polychaete worm found on the west coast of North America and also in Japan. The worms live out of sight in burrows under the sand and produce casts which are visible on the surface.
Lagis koreni, commonly known as the trumpet worm, is a species of marine polychaete worm found in European waters. It lives within a narrow conical tube made of grains of sand and shell fragments.
The annelids, also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments.
Phyllodoce mucosa is a species of polychaete worm in the family Phyllodocidae. It is found intertidally in both the Pacific and Atlantic Oceans, typically on sandy or muddy seabeds.
Phyllodocidae is a family of polychaete worms. Worms in this family live on the seabed and may burrow under the sediment.
Scolelepis squamata is a species of polychaete worm in the family Spionidae. It occurs on the lower shore of coasts on either side of the Atlantic Ocean.
Glycymeris yessoensis is a species of bivalve mollusc in the family Glycymerididae. It can be found burrowing in soft sediment in shallow water in the Pacific Ocean around the coasts of China and Japan. It is often associated with a polychaete worm with which it forms a commensal relationship.
Parahololepidella is a genus of marine annelids in the family Polynoidae. The genus contains a single species, Parahololepidella greeffi, This species is known from the east equatorial Atlantic Ocean and Cape Verde Islands at a maximum depth of 30m.
Hartmania is a genus of marine polychaete worms belonging to the family Polynoidae, the scaleworms. Hartmania contains a single species, Hartmania moorei which is known from the north-west Atlantic Ocean off the coast of North America from shallow water to depths of about 80 m.
Diopatra claparedii is a species of tube-building polychaete worm of the family Onuphidae. It is found dispersed along intertidal and subtidal benthic environments of South Asian waters, especially along the coasts of Malaysia, Singapore, Thailand, and the Philippines. This species is exploited by humans for fishing bait, indication of marine pollution, and as gold and silver nanoparticle biosynthesis agents.
