Stygichthys is a monospecific genus of freshwater ray-finned fish belonging to the family Acestrorhamphidae, the American tetras. The only species in the genus is Stygichthys typhlops. This taxon is endemic to caves in northern Minas Gerais, Brazil. Like other cave-adapted fish, the Brazilian blind characid is blind and lacks pigmentation. It reaches up to about 4.6 cm (1.8 in) in standard length. It is solitary and when kept together in an aquarium, individuals are indifferent to each other.