What are Polychaetes?

The class Polychaeta (poly-keet-a, meaning "many bristles") consists of a very diverse group of segmented worms (unlike round worms or flatworms, which are not segmented) which primarily live in ocean habitats. The closest relatives of polychaetes are the earthworms and leeches. Among the over 80 polychaete families and more than 10,000 species there is an amazing array of body forms and sizes.

Polychaete worms live in every type of habitat in the seas - they can be found in the sands of any beach, all the way down to the deepest depths of the oceans. Most polychaetes make the sea floor their home, where they burrow through sand and mud, or crawl over the sediment surface. Because of their vast abundance, polychaetes comprise an extremely important link in ocean food chains. As a result, polychaetes are one of the most important groups of organisms for assessing the health of marine ecosystems.

Although polychaetes are largely unknown to most people that visit the seashore, our understanding of the impacts of human activities on the oceans can only be accurately monitored through the careful study of these denizens of the deep.