The beardfishes consist of a single extant genus, Polymixia, of deep-sea marine ray-finned fish named for their pair of long hyoid barbels. Until recently they were classified in their own order Polymixiiformes /pɒliˈmɪksi.ɪfɔːrmiːz/. But as Nelson says, "few groups have been shifted back and forth as frequently as this one, and they were recently added to Paracanthoptergii". For instance, they have previously been classified as belonging to the Beryciformes. They are of little economic importance.