What is the order of annelida?
Critical appraisal. Most authors accept the annelids as having three major classes: Polychaeta, Oligochaeta, and Hirudinea. Older systems would place the polychaetes and oligochaetes under the class Chaetopoda because both groups possess setae.
What is the meaning of Polychaeta?
The Polychaeta /ˌpɒlɪˈkiːtə/, also known as the bristle worms or polychaetes, are a paraphyletic class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin.
Do annelids have an open or closed circulatory system?
Annelida. While some small segmented worms of the phylum Annelida have no separate circulatory system, most have a well-developed closed system.
What does polychaete mean in Latin?
adj. (Animals) of, relating to, or belonging to the class Polychaeta. [C19: from New Latin, from Greek polukhaitēs: having much hair; see chaeta]
What is the meaning of chaeta?
chaeta. / (ˈkiːtə) / noun plural -tae (-tiː) any of the chitinous bristles on the body of such annelids as the earthworm and the lugworm: used in locomotion; a seta.
What is the function of parapodia?
Parapodia are paired, unjointed lateral appendages found in polychaete worms, which are often fleshy (especially in marine polychaetes) and used for locomotion, respiration, and other functions.
What eats the polychaete worm?
Polychaetes play an important role in marine food chains. Polychaetes also include active predators, scavengers and grazers of algae. Many polychaetes are eaten by other polychaetes and other marine invertebrates as well as fish and wading birds.
Is there a higher classification for polychaetas?
Higher classification within Class Polychaeta has been somewhat a matter of opinion for many years and consequently taxonomists have not enthusiastically embraced the schemes proposed so far. Here for comparison are two possible modern hierarchies which we shall call Updated-Pettiboneand (late 1997) Cladistic-Rouse- Fauchald.
What are the body segments of a polychaete made of?
Polychaete. The Polychaeta /ˌpɒlɪˈkiːtə/, also known as the bristle worms or polychaetes, are a paraphyletic class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin.
How did the world Polychaeta database come about?
The World Polychaeta Database arose from a merger in 2007 of the massive World Register of Polychaeta compiled privately over many years by the late Kristian Fauchald (Smithsonian Institution) with the European Register of Marine Species ( ERMS ), and some other regional compilations including for Antarctic seas, which were already online.
Is the Polychaeta part of the Linnean family?
The new classification does not use Linnean categories. The Polychaeta comprises two clades, the Scolecida (no further clades above family) and Palpata with clades Aciculata ( = Phyllodocida & Eunicida) and Canalipalpata ( = Sabellida, Spionida, and Terebellida). The Pogonophora are included as the Family Siboglinidae in the clade Sabellida.
