Am pleased to say I was able to purchase one polleni or black Diamond. It is a juvenile approx.one and one half inches long and appears to be in good health. Found it in a shop in Chicago through E-bay. I first saw one some fifteen years ago at a lawyers office and thought it was perhaps the most interesting fish I had ever seen. He will soon (after quarantine) have the run of a 75 gal tank. With some corys and a raphael catfish. Hopefully by the time he displays the coloration they are noted for I will have the know how to post pictures.
The most important medication in your fish medicine cabinet is.. Clean water.