A chaeta or cheta is a chitinous bristle or seta found in annelid worms,. 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.
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.
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.
Swima bombiviridis is a worm species that lives in the deep ocean. It is also known as the green bomber worm or bombardier worm. This deep ocean pelagic (free-swimming) annelid has modified bioluminescent gills that can be cast off from an individual. These discarded gills somewhat resemble green "bombs" that remain illuminated for several seconds after they have been discarded. It is thought that this is a defensive mechanism rather than reproductive, as it is seen in both mature and juvenile individuals. This species was the first of its genus, Swima, to be discovered, and was the only one with a formal scientific name as of 2010. The genus name, Swima, is derived from the Latin, referring to the animal's ability to swim. The species name, bombiviridis, is derived from the Latin prefix bombus, meaning humming or buzzing, and the suffix viridis, which is Latin for the color green. Swima bombiviridis therefore translates to "swimming green bomber".
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.
Alitta succinea is a species of marine annelid in the family Nereididae. It has been recorded throughout the North West Atlantic, as well as in the Gulf of Maine and South Africa.
Sabellastarte spectabilis is a species of benthic marine polychaete worm in the Sabellidae family. It is commonly known as the feather duster worm, feather duster or fan worm. It is native to tropical waters of the Indo-Pacific but has spread to other parts of the world. It is popular in aquariums because of its distinctive appearance and its ability to remove organic particles and improve water quality.
Flabelligeridae is a family of polychaete worms, known as bristle-cage worms, notable for their cephalic cage: long slender chaetae forming a fan-like arrangement surrounding the eversible head. Unlike many polychaetes, they also have large, pigmented, complex eyes.
Eunoe barbata is a scale worm, described from Puget Sound and Monterey Bay in the North-east Pacific Ocean.
Eunoe purperea is a scale worm described from the North Atlantic Ocean off Bermuda at depths of about 900–1600m.
Eunoe shirikishinai is a scale worm described from Hokkaido Island in the North Pacific Ocean.
Hermadionella nipponicus is a scale worm known from Japan in the north-west Pacific Ocean from the intertidal zone.
Bathynoe is a genus of marine annelids in the family Polynoidae. The genus includes two species, both known from depths of about 5000 m.
Bruunilla natalensis is a deep-sea scale worm that is known from a single specimen collected from the Mozambique Basin in the Indian Ocean from a depth of about 5000 m.
Maldanidae is a family of more than 200 species of marine polychaetes commonly known as bamboo worms or maldanid worms. They belong to the order Capitellida, in the phylum Annelida. They are most closely related to family Arenicolidae, and together form the clade Maldanomorpha.
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.
Flotidae is a family of pelagic polychaete worms, sometimes synonymized with Flabelligeridae, which they closely resemble. Other sources consider them the sister taxon to Flabelligeridae and closely allied to the latter group.
Flabelligera is a genus of polychaetes in the family Flabelligeridae. Species are common around the world, in both temperate and cold waters. Flabelligera species have long, club-like papillae, which are encased in a smooth mucus sheath. They also have a distinct cephalic cage, and hooked neurochaeatae which they use to hold onto rocks.
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.
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.
