The phylum Annelida consists of over 9000 species of burrowing, segmented worms. Annelids are characterized by a long body cavity (coelom) divided into many repeating body segments with bristly hairs or "chaetae" attached. Polychaeata (marine worms) is the largest group of Annelids, with over 8000 species.
Polycheates exist in all saltwater habitats from shallow, intertidal pools to the deep ocean and comprise a large amount of marine biomass. This group has parapodia or paddle-like appendages with many chaetae attached, that are used for walking and swimming. Polycheates also grip with the chaetae and burrow using repeated muscle contractions or "peristalsis."
Polychaetes generally reproduce sexually but can also reproduce asexually, via budding or "epitoky". Epitoky occurs when the tail end of the worm grows eyes and gonads and breaks away from the body into a new individual called an epitoke, which is then capable of reproduction.
(Information from
Gulf of Mexico Origin, Waters, and Biota: Volume 1, Biodiversity,
Texas A&M University Press 2009).
Other Resources:
UC Berkeley, Museum of Paleontology, Annelids
