Lou Han is one of the many popular ornamental fish and comes from the family Cichlidae. Hybridization between Lou Han can produce very good quality with certain physical characteristics, namely the aspects of color, facial and beauty of form. One of the factors that influence the color change of Lou Han fish is feeding on fish as well as genetic factors. There are a lot of Lou Han food products sold in the market and offer their own advantages, among others, to grow, change colors, scale and appearance of pearls, so unnerve consumers to select it.
source: http://anton182.wordpress.com/2009/07/03/353/