1 The population density in Parkersburg is 3367% higher than West Virginia. 2  The median age in Parkersburg is 1% higher than West Virginia. 3  In Parkersburg 95.35% of the population is Caucasian. 4  In Parkersburg 1.77% of the population is African American.  In Parkersburg 0.47% of the population is Asian.
The Polychaeta 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. Indeed, polychaetes are sometimes referred to as bristle worms.
Learn more about this article. The annelids (Phylum Annelida) are also called the segmented worms due to their segmented bodies. This group includes the most familiar of all invertebrate worms.Earthworms, freshwater worms, leeches, and marine worms are all annelids.This group is also called bristle worms because most annelids have tiny chitinous bristles called setae. The setae help terrestrial annelids grip their surroundings, and they aid aquatic forms with swimming.arthworms, freshwater worms, leeches, and marine worms are all annelids. This group is also called bristle worms because most annelids have tiny chitinous bristles called setae. The setae help terrestrial annelids grip their surroundings, and they aid aquatic forms with swimming.