See text Sand knifefish are freshwater electric fish of the family Rhamphichthyidae, from freshwater habitats in South America.

[1] Just like most part of the members of the Gymnotiformes group, they also have elongated and compressed bodies and electric organs.

[1] Teeth are absent in the oral jaws and the snout is very long and tubular.

[2] They are nocturnal and burrow in the sand during the day.

[1] According to FishBase there are only three genera in this family,[1] but a comprehensive molecular study from 2015 showed that two additional genera belong here (formerly in Hypopomidae, marked with stars* in list),[3] and this has been followed by recent authorities.