The fish, which is a member of the auchenipterid subfamily Centromochlinae was found in the Rio Sao Francisco basin in Brazil and has been named Glanidium bockmanni.
The description of the new fish published in the latest issue of the journal Copeia says that the new Glanidium lives alongside Glanidium albescens in Minas Gerais.
The two fish can be told apart from their adult sizes, fin ray counts, number of ribs and vertebrae and the serrations of the pectoral fins.
The new catfish also has a distinctive colour pattern: "Within Glanidium, the new species uniquely shares with G. cesarpintoi (Ihering, 1928) a color pattern of small dark dots scattered over the body, a smaller adult size (less than 50 mm in standard length), and absence of first nuchal plate."
For more details see the paper: Luisa Maria Sarmento-Soares, and Paulo A. Buckup (2005) - A New Glanidium from the Rio So Francisco Basin, Brazil (Siluriformes: Auchenipteridae: Centromochlinae). Copeia: Vol. 2005, No. 4, pp. 846-853.