Sedentary polychaetes are a group of marine worms belonging to the class Polychaeta. Unlike their more mobile relatives, these worms live in fixed habitats, often burrowing into the sediment or constructing tubes from sand, mud, or organic materials. They play a crucial role in the ecosystem by aerating the sediment and recycling nutrients. These worms have specialized structures called parapodia that help them anchor themselves and can also assist in feeding. Sedentary polychaetes often have a diverse diet, consuming detritus, plankton, and microorganisms. Their presence contributes to the overall health of marine environments.