While the exact number of discus species and their taxonomies are disputed from source to source, it is understood that the Common Discus one of the distinct species of discus. The Common Discus (Symphysodon aequifasciatus) can actually be separated into three distinct subspecies, based upon coloration. These sub species include brown, green, and blue. The Common Discus is slightly smaller than the Heckel discus, with a size of around 6 inches, but has a relatively similar life span of 4 to 10 years.
Firstly, the brown discus (Symphysodon aequifasciatus axelrodi), named after Dr. Herbert Axelrod, can vary in coloration from a rusty red-brown color to a more light brown hue. Like many other discus species, it has many vertical stripes that run across its body, known as transverse lines, which are most prominent around its fins. On its head, the transverse lines display an iridescent blue color. In the past, this was one of the most popular subspecies of Common Discus due to its relatively easy care and maintenance, thanks to high level of strength and endurance. As many new, more colorful strains have become available in recent years, though, popularity has shifted.
The blue discus (Symphysodon aequifasciatus haraldi) typically embodies a coloration that ranges from dark blue to a purplish brown on the body. One of the defining characteristics of the blue discus is the presence of the easily recognizable longitudinal blue stripes and dark bands that span the length of its body. The blue discus is one of the more popular subspecies with aquarists, as many manmade variations of this specific type. One of the most popular strains, the Cobalt Blue Discus, has a very visually appealing metallic sheen of iridescent blue. Another popular strains, the Royal Blue Discus, displays bold, contrasting colors such as blue and yellow.
The last subspecies of Common Discus, the green discus (Symphysodon aequifasciatus aequifasciatus) can be further separated into two different wild strains, the Lake Tefe Discus and the Pellegrin Green Discus. Green discus that inhabit Lake Tefe, one of its native regions, have a distinct coloration that is noticeably greener than other subspecies. Discus from this area embody a coloration that can be almost fully green, including the iridescent transverse lines that are located along its body. The Pellegrin Green Discus, sometimes called the Peruvian Green, is the name given to green discus that can be found in rivers further away in Peru in the Peruvian Amazon. In comparison to its relatives in Lake Tefe, the Pellegrin Discus is more multicolored. With green being the main coloration, different shades and hues of red can be seen along the anal fins and the dorsal fin. The transverse lines of the Pellegrin Discus also have some hints of red to red brown intermingled within them. Unlike other discus species, the female green discus is noticeably larger than its male counterpart. In the wild, green discus are native to Lake Tefe, the Tefe River, Santarem, Brazil, the Amazon and its tributaries, and the Peruvian amazon.