The nephtyids are inhabitants of sandy mud of coastal, estuarine and offshore waters. They burrow actively means of their eversible proboscis which can be distended by coelomic fluid. They are also active swimmers by producing rapid lateral undulations. They are suspected of being carnivores and selective omnivores. They do not construct permanent tubes. Species found in Singapore include: Aglaophamus dibranchis Nephthys sphaerocirrata