Terebellida

Terebellida
Cirriformia capensis (Cirratulidae)
Scientific classification
Kingdom:	Animalia
Phylum:	Annelida
Class:	Polychaeta
Subclass:	Canalipalpata
Order:	Terebellida
Families
Several, see text

Several, see text

Terebellida make up an order of the Polychaeta class, commonly referred to as "bristle worms". Together with the Sabellida, the Spionida and some enigmatic families of unclear taxonomic relationship (e.g. the Saccocirridae), they make up the subclass Canalipalpata, one of the three main clades of polychaetes. Like most polychaetes, almost all members of the Terebellida are marine organisms. Most are small, sessile detritivores (deposit feeders) which live in small tubes they build from mud or similar substrate, or burrow in the sand. Their central nervous system displays characteristic apomorphies.

There is little consensus on the number of families. Some treatments accept as little as five, while other authors list over a dozen. Here, the more inclusive view of the Terebellida is followed, based on a major review of polychaete systematics.Cladistic studies have hitherto only analyzed a rather small proportion of polychaetes; hence it may be that some of the families today included in Terebellida by most authors will eventually be again recognized to belong elsewhere.

Alvinella pompejana, an Alvinellidae

Cirratulus cirratus, a Cirratulidae

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