Maldanidae

Maldanidae is a family of more than 200 species of marine polychaetes commonly known as bamboo worms or maldanid worms. They belong to the order Capitellida, in the phylum Annelida. They are most closely related to family Arenicolidae, and together form the clade Maldanomorpha.

==Morphology== Maldanid worms have a long and cylindrical body that usually bends at one or both ends. It can be divided into four parts: 1) a head, formed by a dorsally positioned prostomium that is fused to the peristomium, sometimes with a flattened cephalic plate; 2) a thorax, formed by the first four chaetigers (i.e. chaetae-bearing segments), usually with strong spines; 3) an abdomen, with several longer chaetigers that are often followed by a number of achaetous (i.e. without chaetae) segments; 4) a posterior end, with a pygidium that contains the anus. The maldanid pygidium takes a wide variety of forms such as conical, plate-shaped and funnel-shape. Sometimes a few prepygidial (i.e. anterior to the pygidium) segments can be observed.