''Eudistylia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of marine

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

worms. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

is ''Eudistylia gigantea'', now accepted as ''Eudistylia vancouveri''. This worm lives in a parchment-like tube with a single opening from which a crown of

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s projects when the worm is submerged. It is a sessile

filter feeder Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...

. the Eudistylia Vancouveri is unique because it has an opiculum which makes it possible to fully retract into the tube when predators are sensed.

Characteristics

The head is formed from 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 ...

and peristomium, which are fused. It bears two bundles of

radiole 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 (including the Sabellidae, Serpulidae, ...

s or feeding tentacles which together form the funnel-shaped multicolored branchial crown divided into two groups on the dorsal and ventral side of the head. Each radiole is pinnately divided and covered in cilia. It has a central stiffening rod of

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

, a number of eyespots and a feeding groove. There are a pair of small palps beside the radioles and a large funnel-shaped mouth. There are about eight thoracic segments and the first has a flange-like collar which secures the worm to the mouth of its tube. The thoracic segments bear two rows of

setae In biology, setae (singular seta ; from the Latin word for "bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. Th ...

or bristles, the notochaetae on the dorsal side are grouped in tufts, while the neurochaetae on the ventral side form a row of small hooks. The abdomen is long and has many segments. The position of the setae on the abdominal segments is reversed, with the notochaetae being hooked and the neurochaetae being tufted. The pygidium at the posterior tip bears the large anus. There is a furrow on the dorsal side of the thoracic and abdominal segments called the faecal groove through which faecal material and gametes are transported to the open end of the tube.

Distribution

Members of this genus are found on the Pacific coasts of Canada, the United States and Mexico. A group of feather duster worms is called a hummuck, when these hummucks are created kelp attaches by the hold fast as to find habitat where are kelps habitat normally wouldn't be.

Species

*'' Eudistylia brevicomata'' (Ehlers, 1905) *'' Eudistylia catharinae'' Banse, 1979 *'' Eudistylia ceratodaula'' (Schmarda, 1861) *''

Eudistylia polymorpha ''Eudistylia'' is a genus of marine polychaete worms. The type species is ''Eudistylia gigantea'', now accepted as ''Eudistylia vancouveri''. This worm lives in a parchment-like tube with a single opening from which a crown of tentacles projects ...

'' (Johnson, 1901) *'' Eudistylia tenella'' Bush, 1904 *'' Eudistylia vancouveri'' (Kinberg, 1866) World Register of Marine Species
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References

{{Taxonbar, from=Q3605424 Sabellida