e length of the body without abrupt changes in the chaetae and parapodia from one to the next.
食性.本目物种一般皆为捕食性动物或腐食性动物。
支序分类关系.本目的三个主要子群体为：鳞沙蚕亚目（Aphroditiformia）、吻沙蚕亚目（Glyceriformia）及沙蚕亚目（Nereidiformia）：There is agreement on the m