The Chaetopteridae are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of marine

filter-feeding Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a specia ...

polychaete worms 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 mad ...

that live in vertical or U-shaped tubes in tunnels buried in the sedimentary or hard substrate of marine environments. The worms are highly adapted to the hard tube they secrete. Inside the tube the animal is segmented and regionally specialized, with highly modified appendages on different segments for cutting the tunnel, feeding, or creating suction for the flow of water through the tube home. The modified segments for feeding are on the 12th segment from the head for members of this family.Ruppert, E., Fox, R., & Barnes, R. (2007). ''Invertebrate Zoology: A functional Evolutionary Approach''. 7th Edition. Belmont:Thomson Learning.

Larvae

Chaetopteridae larvae are the largest among the

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

worms. The larvae will range in size from 0.4 mm to 2.5 mm (largest polychaete larvae reported having a maximum length of 12 mm; the late stage of an unknown phyllodocid species). Chaetopteridae larvae are barrel-like in form with one to two ciliated bands at the midsection. They also have a large buccal funnel. These larvae are often long lived and effectively

disseminate To disseminate (from lat. ''disseminare'' "scattering seeds"), in the field of communication, is to broadcast a message to the public without direct feedback from the audience. Meaning Dissemination takes on the theory of the traditional view ...

, although are constrained geographically to their appropriate ranges for successful adult growth. The most common form of larval developmental plan for polychaetes is the

trochophore A trochophore () is a type of free-swimming planktonic marine larva with several bands of cilia. By moving their cilia rapidly, they make a water eddy to control their movement, and to bring their food closer in order to capture it more easily. ...

larvae. The trochophore will add segments sequentially from a posterior growth zone to produce a

nectochaete A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

larva. ''Chaetopterus'' represents a distinct deviation from this general design. At no point in larval growth stages does the metatrochophore take on the clearly segmented form of the typical nectochaete larva. The 15 segments of ''Chaetopterus'' are formed by subdivision of existing anlage.

Feeding

The Chaetopteridae have several genera with peculiar and well-studied

mechanisms. The genera ''

Chaetopterus ''Chaetopterus'' or the parchment worm or parchment tube worm is a genus of Marine (ocean), marine polychaete worm that lives in a tube it constructs in sediments or attaches to a rocky or coral reef substrate. The common name arises from the par ...

'', '' Mesochaetopterus'', and '' Spiochaetopterus'' feed using a thin mucus net suspended across the upper portion of their tube. The mucus net is secreted by a hooplike structure called the aliform

notopodia In invertebrates, the term parapodium (Greek language, Gr. ''para'', beyond or beside + ''podia'', feet; : parapodia) refers to lateral outgrowths or protrusions from the body. Parapodia are predominantly found in Annelid, annelids, where they ar ...

arch. The net can grow at a rate as great as one millimeter per second as water currents generated by the

l fans pass

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

through the net. When the net grows large enough it contacts the

cilia The cilium (: cilia; ; in Medieval Latin and in anatomy, ''cilium'') is a short hair-like membrane protrusion from many types of eukaryotic cell. (Cilia are absent in bacteria and archaea.) The cilium has the shape of a slender threadlike proj ...

ted cup, which rolls up the net. When the roll becomes large the net is disconnected from the aliform notopodia and is rolled into a ball before the

ted mid-

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

groove transports it to the mouth.

Affinity

Molecular analysis suggests that this group is basal within the annelids, below the sipunculid worms.

Genera

The

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

lists the following genera as being in the family: *''

'' Cuvier, 1830 *'' Mesochaetopterus'' Potts, 1914 *'' Mesotrocha'' Leuckart & Pagenstecher in Leuckart, 1855 *'' Phyllochaetopterus'' Grube, 1863 *'' Spiochaetopterus'' M Sars, 1856

References

{{Authority control Canalipalpata Annelid families