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.
Lesson Summary. Annelida is the phylum that contains the segmented worms. These worms all have segmented bodies that are bilateral and contain the same structures in each segment, with exceptions of the head and anus of the animal. Since these animals are fairly simple, there are few highly specialized digestive structures.