Chaetopterus also called parchment worm or parchment tubeworm is really a member of the phylum Annelida. The parchment worm is really a marine polychaete worm that dwells within the tube which it constructs by sediments or attaches to any coral reef substrate. It's called parchment worm because of the parchment kind of tube the worm makes. They're filter feeders and also the adults dwell completely in their entire lives in the tube unless and before tube is destroyed or damaged somehow. The children feed on planktons which is a typical feature one of the phylum Annelida.

The tubes from the worms are either connected to the rocks or can be found in the sandy bottom close to the shallow waters. Your body of the worm is thrown into segments and also the whole body is provided with spines that are used for tunneling while the worm is busy for making the burrow. The worm may make a U-shaped burrow by which it finally lives. The tubes are lined with mucus. The tubes measure 85 cm long and 4 cm across. The center of the tube may be the widest area. The worm is extremely specialized among the polychaetes since the middle segments from the body bear highly specialized parapodia adapted to sign up in filter feeding. The parapodia are large in dimensions and are fan-shaped which are accustomed to create suction and pump water with the tube. The morphology of parapodia can be used in the identification of species. The worm feeds by utilizing specialized structures present about the mid-body segments that secrete mucus for trapping the meals particles. A flow of water is done by three circular flaps about the three segments that can cause suction and draws water for the tube.

They lack any organ able to detecting light since the worm passes its entire life buried within the tube. Apart from this kind of habitat few species are recognized to exhibit bioluminescence. When the worm is disturbed in the burrow it moves from the point of disturbance and secrets mucus for the disturbance point which crystallizes and emits bioluminescence of blue colour. Two types of filter feeding crabs owned by two different people are known to dwell within the tubes of these worms. Aside from these two species another one is also known to inhabit the worm's tube sometimes. Polyonyx and Pinnixa are commonly found to dwell within the tube of the parchment worm. They might be present together also. The breeding pairs don't share the tube with crabs along with other species of animals. The crabs tend to dwell within the tubes and leave the tubes only if disturbed.