Phyllodocida is an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

polychaete 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 ...

worms in the subclass Aciculata.World Register of Marine Species
/ref> These worms are mostly marine, though some are found in

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

. Most are active

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

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 The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...

, swimming through the

water column A water column is a conceptual column of water from the surface of a sea, river or lake to the bottom sediment.Munson, B.H., Axler, R., Hagley C., Host G., Merrick G., Richards C. (2004).Glossary. ''Water on the Web''. University of Minnesota-D ...

. There are estimated to be more than 4,600 accepted

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

in the order.

Characteristics

Phyllodocida are segmented worms and range in size from a few millimetres long to over a metre. Each segment bears a pair of paddle-like

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

. The

prostomium The prostomium (From Ancient Greek, meaning "before the mouth"; plural: prostomia; sometimes also called the "acron") is the cephalized first body segment in an annelid worm's body at the anterior end. It is in front of (but does not include) th ...

generally has one or two pairs of eyes, a dorsal pair of antennae, a ventral pair of sensory palps and a pair of organs on the neck. The peristomium is a ring, often hidden dorsally by the prostomium and the first segment. There is a muscular

proboscis A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elonga ...

with one or more pairs of jaws. The next few segments tend to differ from those further back in having enlarged dorsal and ventral cirri (fine appendages) and reduced parapodial lobes and

chaeta A chaeta or cheta (from Greek χαίτη “crest, mane, flowing hair"; plural: chaetae) is a chitinous bristle or seta found in annelid worms, (although the term is also frequently used to describe similar structures in other invertebrates such ...

e (bristles). Some species have appendages with specialised functions but most have many segments that are similar to each other but which vary in size and shape along the length of the body without abrupt changes in the chaetae and parapodia from one to the next.Tree of Life Web Project
/ref>

Biology

Worms in this order are generally predators or

scavenger Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...

Phylogenetic relationships

The three main subgroups are Aphroditiformia, Glyceriformia and Nereidiformia. The Aphroditiformia are characterised by the presence of elytrae or scales on alternating segments. The Glyceriformia are characterised by the presence of unique cone-shaped and ringed prostomiums. The Nereidiformia are more problematic, having no universally distinguishing common features. There is agreement on the

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...

of a group including the Hesionidae, Nereididae and Chrysopetalidae families but opinions differ about Pilargidae, and molecular and morphological studies continue.Dahlgren, T.G., Lundberg, J., Pleijel, F., and Sundberg, P. 2000. Morphological and molecular evidence of the phylogeny of Nereidiform polychaetes (Annelida). J. zool. Syst. evol. Res. 38:249-253.

Families

Recognised families: Suborder Aphroditiformia :Superfamily Aphroditoidea ::

Acoetidae Acoetidae is a family of polychaete worms in the subclass Aciculata. Genera * '' Acoetes'' Audouin & Milne Edwards, 1832 * '' Euarche'' Ehlers, 1887 * '' Eumolpe'' * '' Eupanthalis'' McIntosh, 1876 * '' Eupolyodontes'' Buchanan, 1894 * '' Eup ...

Aphroditidae Aphroditidae is a family of annelids belonging to the order Phyllodocida. Genera Genera: * ''Aphrodita ''Aphrodita'' is a genus of ocean, marine polychaete worms found in the Mediterranean sea and the eastern and western Atlantic Ocean. S ...

Eulepethidae Eulepethidae is a family of polychaetes belonging to the order Phyllodocida 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 benthi ...

Pholoidae Pholoidae is a family of polychaetes belonging to the order Phyllodocida. Genera: * '' Imajimapholoe'' Pettibone, 1992 * '' Laubierpholoe'' Pettibone, 1992 * '' Metaxypsamma'' Wolf, 1986 * ''Pholoe Foloi ( el, Φολόη, Latin: ''Pholoe'') is a ...

:: Polynoidae :: Sigalionidae :Superfamily Chrysopetalacea ::

Chrysopetalidae Chrysopetalidae is a family of polychaete worms. The body is short or elongated, with few or numerous segments. All segments bear on their dorsal side a fan or a transverse row of paleae. The cephalic lobe has tentacles and eyes and the buccal se ...

:Superfamily Pisionacea :: Pisionidae Suborder Glyceriformia ::

Glyceridae Glyceridae is a family of polychaete worms. They are commonly referred to as beak-thrower worms or bloodworms. They are bright red, segmented, aquatic worms. The proboscis worm '' Glycera'' is sometimes called bloodworm. The Glyceridae are epi- a ...

:: Goniadidae ::

Lacydoniidae Lacydoniidae is a family of polychaetes belonging to the order Phyllodocida. Genera: * '' Lacydonia'' Marion, 1874 References Polychaetes {{Annelid-stub ...

:: Paralacydoniidae Suborder Nereidiformia :: Antonbruuniidae ::

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 o ...

:: Nereidae :: Pilargidae :: Syllidae Suborder Phyllodocida

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

:: Iospilidae ::

Nephtyidae Nephtyidae is a family of polychaete worms. They are commonly referred to as catworms. Characteristics Nephtyidae are pale, clearly segmented polychaetes with a small pentagonal prostomium with two pairs of small antennae. Their segments are litt ...

Sphaerodoridae Sphaerodoridae is a family of polychaetes belonging to the order Phyllodocida 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 bent ...

:: Tomopteridae ::

Typhloscolecidae Typhloscolecidae is a family of polychaetes belonging to the order Phyllodocida. Genera: * ''Acicularia ''Acicularia'' is a genus of green algae in the family Dasycladaceae The Dasycladaceae is one of the two extant families of green algae ...

:: Yndolaciidae Suborder

Phyllodociformia 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 cr ...

Alciopidae Alciopidae is a family of polychaetes belonging to the order Phyllodocida 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 c ...

Lopadorhynchidae Lopadorrhynchidae is a family of polychaete worms. References External links * Lopadorrhynchidaeat the World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an autho ...

:: Phyllodocidae :: Pontodoridae

Incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

:: Nautiliniellidae

References

External links

{{Taxonbar, from=Q733080 Protostome orders Annelid orders