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.
A chaeta or cheta is a chitinous bristle or seta found on annelid worms, although the term is also frequently used to describe similar structures in other invertebrates such as arthropods. Polychaete annelids are named for their chaetae. In Polychaeta, chaetae are found as bundles on the parapodia, paired appendages on the side of the body. The chaetae are epidermal, extracellular structures, and clearly visible in most polychaetes. They are probably the best-studied structures in these animals. Segments bearing chaetae are called chaetigers.
Sabellida is an order of annelid worms in the class Polychaeta. They are filter feeders with no buccal organ. The prostomium is fused with the peristomium and bears a ring of feathery feeding tentacles. They live in parchment-like tubes made of particles from their environment such as sand and shell fragments cemented together with mucus.
Spirobranchus giganteus, commonly known as the Christmas tree worm, is a tube-building polychaete worm belonging to the family Serpulidae. The S. giganteus lives in coral reefs in the Indo-Pacific region to the Caribbean.
Spirobranchus is a small genus of tube-building annelid fanworms in the family Serpulidae.
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.
Serpula is a genus of sessile, marine annelid tube worms that belongs to the family Serpulidae. Serpulid worms are very similar to tube worms of the closely related sabellid family, except that the former possess a cartilaginous operculum that occludes the entrance to their protective tube after the animal has withdrawn into it. The most distinctive feature of worms of the genus Serpula is their colorful fan-shaped "crown". The crown, used by these animals for respiration and alimentation, is the structure that is most commonly seen by scuba divers and other casual observers.
A radiole is a heavily ciliated feather-like tentacle found in highly organized clusters on the crowns of Canalipalpata. Canalipalpata is an order of sessile marine polychaete worms consisting of 31 families. These benthic annelid tube worms employ radioles primarily for alimentation. While their primary role is to function as an organ for filter feeding, radioles also serve as respiratory organs. Because of their role in gas exchange, radioles are often referred to as "gills".
Thylacodes arenarius is a species of sea snail, a marine gastropod mollusk in the family Vermetidae, the worm snails or worm shells.
Janua pagenstecheri is a species of marine polychaete. It is widely distributed around the British Isles and across north-western Europe, and has been described as "probably the commonest spirorbid in the world".
Janua is a genus of polychaetes, containing the following subgenera and species:
Spionida is an order of marine polychaete worms in the infraclass Canalipalpata. Spionids are cosmopolitan and live in soft substrates in the littoral or neritic zones.
Biomineralising polychaetes are polychaetes that produce minerals to harden or stiffen their own tissues (biomineralize).
Ficopomatus enigmaticus, commonly known as the Australian tubeworm, is a species of serpulid tubeworms. Their true native range is unknown, but they probably originated in the Southern Hemisphere, perhaps from the Indian Ocean and the coastal waters of Australia. Today they have a cosmopolitan distribution, having been introduced to shallow waters worldwide. The Australian tubeworm is an invasive species that dominates and alters habitats, reduces water quality, depletes resources, and causes biofouling.
Polydora is a genus of annelid worms. It contains marine polychaete species that live in mud, holes bored in rocks, and holes bored in the shells of shellfish.
Olev Vinn is an Estonian paleobiologist and paleontologist.
Poeobius is a genus of marine polychaete worm. It contains the single species Poeobius meseres, or balloon worm. This is a common and abundant resident in the midwater around the mesopelagic and bathypelagic zones, especially in Monterey Bay. They can be found at around 300-2,500 m depth from Japan to Alaska to the Gulf of California, and have also been reported in South America.
Olga Hartman was an American invertebrate zoologist and polychaetologist. She was a student of S. F. Light at the University of California, Berkeley, and later a staff researcher at the Allan Hancock Foundation and professor of biology at the University of Southern California. Active from the 1930s to the 1970s, Hartman specialized in Polychaeta, a class of marine annelid worms, and was known for her work as a cataloger and as a polychaete systematist. She is considered one of the top three most prolific authors in her field, having described 473 polychaete species during her lifetime.
