''Sabella pavonina'', commonly known as the peacock worm, is a marine

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 ...

worm Worms are many different distantly related bilateria, bilateral animals that typically have a long cylindrical tube-like body, no limb (anatomy), limbs, and usually no eyes. Worms vary in size from microscopic to over in length for marine ...

belonging to the family

Sabellidae Sabellidae, or feather duster worms, are a family of marine polychaete tube worms characterized by protruding feathery branchiae. Sabellids build tubes out of a tough, parchment-like exudate, strengthened with sand and bits of shell. Unlike th ...

. They can be found along the coasts of

Western Europe Western Europe is the western region of Europe. The region's extent varies depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the Western half of the ancient Mediterranean ...

and the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

. It is found in shallow, tidal waters with a bed of mud, sand or gravel. It is sometimes found on rocks or

shipwreck A shipwreck is the wreckage of a ship that is located either beached on land or sunken to the bottom of a body of water. It results from the event of ''shipwrecking'', which may be intentional or unintentional. There were approximately thre ...

s. It is in length. Its body is elongated and divided into 100–600 small segments. The head has two fans of 8–45 feathery

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, Serpulida ...

s arising from fleshy, semi-circular lobes. The body is mostly grey-green while the radioles are brown, red or purple with darker bands. The worm lives inside a smooth tube of fine mud or sand particles held together with

mucus Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...

. The tube stands upright with the lower end attached to stones and the upper end protruding from the sea bed. When covered by water, the worm extends its crown out of the tube to feed, using

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 ...

on the radioles to circulate water through the crown. Small food particles are carried down the radioles to the mouth of the worm, while larger particles are rejected, or cemented with mucus to extend the length of the tube. The crown is highly sensitive to light and pressure and quickly retracts in response to motion or shadow. ''Sabella pavonina'' and other Sabellid worms experience heavy predation by bottom-feeding fish, but are capable of regenerating even when a large part of the tube and the worm inside have been bitten off.

References

External links

Peacock worm
at Marine Life Information Network
ARKive - images and video
* {{Taxonbar, from=Q1171262 Sabellida Fauna of the Atlantic Ocean Fauna of the Mediterranean Sea Animals described in 1820 Taxa named by Marie Jules César Savigny