Stygichthys Brittan & Böhlke, 1965

The position of this genus within Characidae is completely enigmatic; even its assignment to the Characidae can not be considered to be well justified. The single species of this genus, Stygichthys typhlops Brittan & Böhlke, has hypogean habits and some unique or much unusual features among the Characidae (Géry, 1977) . The presence in this species of a very short anal fin with only eight rays is unique within the Characidae . No information relevant to a hypothesis about the relationships of this genus is available and Stygichthys is maintained as incertae sedis within the Characidae .