Sternarchorhynchus is a genus of ghost knifefishes with a long, decurved snout that are found in river basins in tropical South America.

[2] S. mesensis is known from both above-ground and below-ground habitats, but lacks the cavefish adaptions seen in the only true cave knifefish, Eigenmannia vicentespelaea.

[4][5] The current conservation status of S. gnomus is unclear, as the only known locality in Venezuela's lower Caroní basin has been flooded by a dam.

They are often darker on the upper part than the lower and some have a pale line on the top of the head, but otherwise they are quite uniformly colored without conspicuous patters.

However, at least one species, S. cramptoni, is overall whitish-pink, similar to some other knifefish like Compsaraia and Orthosternarchus that inhabit deep, dark rivers.