Errant species

Segmented worms are generally found along the bottom, living in deposits of sediment or under rocks. Some types build tubular homes for themselves in which they spend their entire lives. These sedentary worms include the parchment tube worm and the trumpet tube worm. Errant species, such as bloodworms and syllid worms, spend some of their time out of their hiding places, actively seeking prey. 

Most information on polychaetes is for errant species of the order Nereidiformia, with very few studies having been carried out on sedentary species. The only enzyme that has been characterized or studied to any degree is the MFO system. Very little information is available on the toxic molecular consequences of biotransformation in polychaetes. 

Others polychaetes are considered to be sedentary because they stay in one place, waiting for food to come to them. Their bodies are often shorter than errant worms, with clearly defined regions. Like the sabellid worm in the lower color insert on page C-2, sedentary polychaetes spend their lives in tubes or holes and have developed a variety of special adaptations for feeding and breathing in these niches. Most of these worms consume plankton or other small material that is suspended in the water. Some species of sedentary polychaetes include the coiled tube worm, sand builder worm, trumpet worm, parchment worm, lugworm, and hard tube worm. 

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