Brisingids are suspension feeders. This taxa contains the single genus Xyloplax with two species, one in the Pacific and one in the Atlantic. Positive determination of the sister taxon to the concentricycloids remains elusive although evidence suggests a relationship with asteroids. This is a deep-sea group, historically placed with the Ophiuridae. Hemieuryalidae Ophionereidae Ophiothricidae Ophiothricids are apparently successful in the tropical Pacific.
Several taxa are epizoic on octocorals and other invertebrates.
Tropical members of this family are also very colorful, often retaining their stunning purples and reds after preservation. Amphiuridae Ophiactidae Echinoidea Cidariida Cidaridae Psychocidaridae Echinothuriida Echinothuriidae Deep-water and tropical echinoids. These all represent exclusively deep-sea fauna.