Phenacogrammus

The Congo tetra, Phenacogrammus interruptus, is a tetra from parts of the River Congo drainage in the Democratic Republic of Congo. Wild populations are endemic there, but most fish in the trade are bred commercially in the Far East and Eastern Europe. Usually sold as a drab, greyish juvenile, it colours up as it matures, and males develop extended caudal filaments and a greatly extended dorsal fin. It is sensitive to water quality and easily frightened when not kept in numbers.