Overview
Polychaeta is the largest class within Phylum Annelida. This class is primarily composed of Marine worms.
Characteristics
- Metameric Body Segmentation
- The body is arranged in metameres, small body
segments.
- Allows compartmentalization in case of injury.
- Allows specialization for certain bodily
functions.
- Parapodium
- Have Setae sticking out of the ends, bristles
which aid in locomotion.
- Prostomium
- Cuticle
- Move by “Undulating”
- Digestive system fitting their food source.
- Some predatory members have jaws with poison
glands for subduing their prey
- Others are herbivorous or filter feeders.
- Closed circulatory system
- Parapodia increase surface area for gas
exchange.
- Nervous System
- Regulate contraction of muscles
- Excretion Systems
- Reproduction
- Mostly Sexual, Dioecious
- Can reproduce by Budding
Sources:
Campbell & Reece. "Biology" Benjamin Cummings. 6th Edition, 661
Miller & Harley. "Zoology" McGraw Hill. 7th Edition, 212-217