Dylan, this is a major topic.
This will be a real
Most all discus available now are raised by breeders; the many colour varieties have been developed from the wild stock over many years through selective breeding. But I am one who still feels the fish will do best when their ancestry is understood and their habitat replicated as much as possible, so we are on the same wavelength. You cannot eradicate millions of years of evolutionary development by a few decades of tank rearing.
All discus belong to the genus Symphysodon
, and although there is some disagreement as to the actual species, everyone agrees there are three. Symphysodon aequifasciata
Pelligrin 1904, S. discus
Heckel 1840, and S. haraldi
Schultz 1960 are the scientifically recognized valid species; the variant "species" names are recognized as synonyms for one of these three. S. aequifasciata
occurs in the western Amazon River basin in Brazil, Columbia and Peru. S. discus
occurs in the lower Rio Negro basin, and S. haraldi
is found in the clearwater lakes and rivers in areas of the Amazon River basin in Brazil, Columbia and (possibly) Peru. The species do not overlap, that is, each is endemic within their respective watercourses.
Given that your discus will most probably not be wild-caught [see * below], you could ascertain the ancestral species and build the aquarium accordingly, or more easily simply select fish from any rivers known to be discus habitat regardless of the species. Or a third and easiest method, select fish that occur in identical habitats in terms of water parameters and environment. This latter consideration will be constant either way: very soft, acidic and warm; slow-flowing streams, thick with plants, dim light, bogwood, etc. Tankmates will have to be compatible, which leaves out neon tetras since Paracheirodon innesi
occurs in cooler streams than any discus. On the other hand, the cardinal tetra, P. axelrodi
, is found throughout the Rio Negro basin in identical habitats to discus. The German or common Ram, Mikrogeophagus ramirezi
, would never be found with discus, but is an admirable tankmate because it needs basically identical water, and it tends to remain close to the substrate (like most dwarf cichlids from SA) while discus prefer mid-tank. Hatchetfish on top would be compatible. And Corydoras sterbai (one of the few corys that can tolerate the warmth), Farlowella, or the Whiptail are admirable other catfish species--and the last two are incredible algae eaters.
*Being in Quebec, you could obtain some from Oliver Lucanus at Below Water in Montreal; he has wild-caught S. tarzoo
[green discus] from Tefe, Brazil, included in his latest fish list this week. This is an example of the "disagreement" over species I mentioned above, S. tarzoo
is officially recognized as a synonym for the valid species S. aequifasciata.
How's that for starters. B.