Synbranchiformes

Synbranchiformes: Body elongate; pelvic fins absent; gill openings confined to lower half of body; ectopterygoid enlarged; mesopterygoid reduced or absent; premaxillary nonprotrusible and without ascending process. All species except three occur in freshwater.
 * See Fishbase.

Families in this order:
 * Chaudhuriidae
 * Mastacembelidae
 * Synbranchidae