Taxon Description (Wikipedia)
The
Polychaeta or
polychaetes are a 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. Indeed, polychaetes are sometimes referred to as
bristle worms. More than 10,000 species are described in this class. Common representatives include the lugworm (
Arenicola marina) and the sandworm or clam worm
Nereis.
Polychaetes as a class are robust and widespread, with species that live in the coldest ocean temperatures of the abyssal plain, to forms which tolerate the extreme high temperatures near hydrothermal vents. Polychaetes occur throughout the Earth's oceans at all depths, from forms that live as plankton near the surface, to a 2–...
full article at Wikipedia
