Doliolidae is a family of tunicates in the order Doliolida. Members of the family are pelagic and often found far away from coastlines. Members of the family are transparent, gelatinous, barrel-shaped or cylindrical marine organisms. They are mostly small and inconspicuous. They have cilia which move water through the mucus nets which they use to trap the phytoplankton on which they feed. This is in contrast to their close relations, the salps, which use contractions of transverse muscles in the body wall for this purpose. Doliolids also have circular muscles, the sudden contraction of which cause them to move rapidly in a characteristic jerky manner.