The family Notopteridae contains ten species of osteoglossiform (bony-tongued) fishes, commonly known as featherbacks and knifefishes. These fishes live in freshwater or brackish environments in Africa, and South and Southeast Asia. With the denotation of "knifefish", the Notopterids should not be confused with Gymnotiforms, the electric knifefishes from South and Central America. Although their manner of swimming is similar and they are superficially similar in appearance, the two groups are not closely related.