Discus are among the most coveted of all tropical aquarium fish. Regarded for their sheer beauty, they appear in a variety of shades, colors, and patterns, all of which contribute to their majesty. Here is an overview of some of the more common forms you may encounter at your local pet shop, along with a basic guide on how to best care for them.
The Discus is one of the more popular aquarium fish in America. Known primarily for their bright, lustrous colors, their flat bodies give them the distinct appearance of discs, hence their name. Hailing from the Amazon, they actually belong to the Cichlid family, known for other, more commonly known fish such as the aggressive Oscar to the more tank-friendly Angelfish. Reaching lengths of about 10 inches or so in diameter, the Discus makes a beautiful addition to a home aquarium, but be warned: This is a fragile animal, and is not recommended for beginners. If you've had trouble in the past keeping Bettas alive, then steer clear.
Color's the key when determining types of Discus. There are essentially two different categories concerning their placement: naturally occurring fish, which, obviously, are animals found in the wild, and cultivated Discus, which are shades and colors that have occurred through generations of selective breeding.
Heckel Discus (Symphysodon Discus): The original Discus, named for its discoverer Johan Heckel. Appearing with a dark stripe down the middle of its side, the fish comes in both red and blue varieties.
Green Discus (Symphysodon Aequifasciatus): The name says it all. The Green Discus appears in many shades, ranging from bright, vivid green to a lighter, more yellowish color. Their sides are dotted with bright red spots and dark stripes.
Brown Discus (Symphysodon Aequifasciatus Axelrodi): One of the more common species, the Brown Discus, while hardier than most others, is generally dull in coloration, usually with faded stripes and occasional color on its fins.
Blue Discus (Symphysodon Aequifasciatus Haraldi): Blue Discus are very similar in coloration to the Brown Discus, except for (duh) a rich blue hue covering their body.
Turquoise Discus: Coming in both red and blue varieties, these fish were created through cross breeding of different species. Blue Turquoises are generally completely blue with red speckles and dark vertical stripes while the Red Turquoises have a white/yellowish body with horizontal, bright red striations.
Pigeon Blood Discus: Created in 1991, Pigeon Bloods have a bright white, sometimes cream-colored body with bright red striations and, most notably, a solid black tail.
Albino Discus: Unveiled in 2000, Albino Discus are a relatively new strain in the hobby. With white bodies and red eyes, many of the more common cultivated Discus have been bred with albinism.
Golden Discus: One of the more vibrant strains, Golden Discus have solid yellow bodies, occasionally patterned with dim white stripes and red eyes with semi-translucent fins.
Blue Diamond Discus: Extremely lustrous, Blue Diamonds are white with a deep, blue hue and red eyes. The fins are usually finer than most other varieties, giving them a twinkling shine. Occasionally, yellow coloring will sneak in underneath the eyes or near the fins.
There are literally hundreds more varieties, most of which are determined by color. Most Discus, though, follow the same basic steps when caring for them.
The Proper Environment
Because Discus originate from South America, it's generally proposed that their best environment would be blackwater, a condition similar to that of the Amazon, whereas soil and the abundance of trees and flaking vegetation create a murky, soft, ecosystem. Though the subject of proper aquarium standards for the varying types of discus is hotly debated among hobbyists, there are some generalities that will work just fine for most.
Water: Most varieties of Discus prefer a pH level between 6.5 to 7.0, but their resiliency (along with most other fish's) is highly underrated, and can generally adapt to levels between 6.0 to 7.4. Like the Amazon, the water should be medium or soft, and in fact there is a chemical known as Blackwater extract available at most pet stores that will aide in simulating the environment. Remember to keep temperature fluctuations to a minimum while trying to maintain a range of around 85 to 90 degrees Fahrenheit. Like all other aquariums, keep a high quality filter, but adjust the dials to keep the current slow (many filters have a dial near the top to help accomplish this).
Tank Size: Rule No. 1: Never listen to pet shop owners who tell you that a fish will only grow to the size of its tank. While this may be true, the fact that they neglect to mention is that the fish will also die a very premature death and have mutilated, curled fins and spend most of its day relaxing in its own urine. Sounds fun. The reality is that those cute baby Discus you may find in pet stores will grow to be at least 6 inches in diameter, sometimes 10, sometimes even larger, so a good sized aquarium is a must. Fifty-five gallon tanks are probably the most common large tank size, but be weary of their narrowness. The tank must be deep, at least 18 inches or so, but also remember you want it to be wide so the fish can, you know, turn around without bonking its head on the glass. Many breeders recommend a tank size of around 75 gallons, allowing proper width and depth.
There are special flakes designed specifically for Discus available at most pet shops, but they will also readily take live foods like brine shrimp (not to dampen your childhood, but these are sea monkeys), mysis shrimp, even baby crickets. Because of the potential risk for insect-borne parasites, though, use live good sparingly.
Temperament and Compatibility
Discus, as mentioned before, are Cichlids, which are known for being territorial and having mood swings. They are fine with other Discus as long as they are around the same size and a properly sized tank. A good rule of thumb is that each Discus needs about 10 to 15 gallons of water to itself. For those who may not be too good at math, a 75-gallon tank can hold about 6 Discus. As far as tank mates go, it's best to find fish that may keep to themselves, like bottom feeders. And remember, if you've done everything properly your Discus will be in a blackwater environment, therefore it's best to have other Amazonian fish, just as long as they're not aggressive.
As a final note, take special care to realize that Discus are not cheap. While some, less colorful varieties run around $20; some range up over $100 for larger, more beautiful specimens. Take this into account when selecting tank mates and remember to follow every guideline when setting up your tank. Waking up and seeing your coveted fish, that also happened to take a big bite out of your wallet, taking a nice relaxing upside-down float is not a good feeling.