Polynemus is a genus of threadfins (family Polynemidae). They are native to South and Southeast Asia and, depending on the species, occur in freshwater, brackish, and/or marine environments. The Polynemidae family is characterized by the pectoral fin that is divided into two sections; the upper one with rays that are attached whereas the lower rays are long and unattached ("threads"). In Polynemus the unattached rays number 14–15, in contrast to 3–7 in other genera.