Pilargidae is 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 ...

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 ...

s. These marine worms are cylindrical, somewhat flattened, and can be ribbon-like. They can be found free-living on sediment, or shallowly in sediment. Some species within the genera Hermundura and Litocorsa are known to burrow, having reduced heads and

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

. Two species are known to be commensal with other polychaetes. ''Pilargis berkeleyae'' will live in the tubes of

Chaetopteridae The Chaetopteridae are a Family (biology), family of marine filter feeding, filter-feeding Polychaete, polychaete worms that live in vertical or U-shaped tubes in tunnels buried in the sedimentary or hard substrate of marine environments. The wo ...

, and ''Ancistrosyllis commensalis'' will live in

Capitellidae Capitellidae is a polychaete worm family in the subclass Scolecida Scolecida is an Infraclass (biology), infraclass of polychaete worms. Scolecids are mostly unselective Detritivore, deposit feeders on marine detritus. Characteristics Scolec ...

burrows. Pilargid worms are almost all exclusively

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

s, classified as

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they ar ...

omnivores An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...

. They are similar in appearance to

Hesionidae Hesionidae are a family of phyllodocid bristle worms (class Polychaeta). They are (like almost all polychaetes) marine organisms. Most are found on the continental shelf; '' Hesiocaeca methanicola'' is found on methane ice, where it feeds on ...

, with a

peristomium The peristomium is the first true body segment in an annelid worm's body in the anterior end. It is directly behind the prostomium and contains the mouth, tentacular cirri, and sometimes feeding palps, which may instead occur on the prostomium. If ...

often with two pairs of tentacular cirri (with 1 pair or 0 in some species), reduced or absent

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 ...

, and a lack of pharyngeal jaws. The first few segments bearing setigers are also somewhat fused. They can have 0 to 3 antennae, and palps. These

polychaetes 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 m ...

are rarely the most abundant polychaete.

Contested genera

Some genera have been redescribed under a new genus, which some consider junior synonyms of existing genera. '' Parandalia tricuspis'' is a redescription of Hermundura tricuspis, which provided more reliable characteristics for identification.

References

External links

Polychaetes Annelid families {{Annelid-stub