some kind of regional varient of myleus schombergkii.
Quoted from a PFK article by Richard Hardwick found here :
http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=383
There are currently three regional variants of the species. Two to me look very similar, but I suspect that the first will soon be described as a different species. This variant sports blue-white finnage with an extremely broad vertical vertical band while the other two have a red anal fin and a narrower black band.
The species is however only imported from time to time, and is collected from Brazil, notably the Rio Negro, Xingu, Araguaia, Venezuela and the Orinoco.