Discus are beautiful blue fish that are usually entirely blue with red patterns / striations on the body, dorsal and anal fins, and on the gill covers. Many of these were originally developed in the United States by Jack Wattley from several crossings of wild and tank raised blue and green discus. There are high bodied, solid blue, red striated, and high finned varieties that have developed thoughout years of selective breeding. Discus originate from the Amazon River Systems of South America, where they were first imported into the aquarium hobby in the early 1930s. Ever since their introduction into the hobby to this day, Discus are considered one of the most colorful, demanding, rewarding and expensive of all tropical freshwater aquarium fish species. Due to their popularity and the high price tag that they command, Discus are very popular with fish breeders. Over the years breeders have not only raised enough tank-bred specimens to largely fulfill the demand from the aquarium hobby, but have developed completely new color strains and patterns as well. Discus are very popular amongst intermediate to advanced fish keepers, and are widely considered to be one of the most rewarding and challenging to keep of the freshwater tropical community fish species available within the hobby.