5-8, see text Psamathini are a tribe of phyllodocid "bristle worms" (class Polychaeta) in the family Hesionidae.
They are (like almost all polychaetes) marine organisms; most are found on the continental shelf, but some have adapted to greater depths down to the abyssal plain.
[1] Their dorsal cirri alternate, and they usually lack facial tubercles.
Most have prolonged teeth on the chaetal blades.
5 genera are placed in the Psamathini with certainty, and three further ones are often included here too in recent times, to make this tribe refer to a distinct clade of polychaetes:[2]