Discus (Symphysodon aequifasciata spp.)

Common Name:

Discus.

Scientific Name:

Symphysodon aequifasciata spp.

Family:

Cichlidae.

Class:

South American Cichlid.

Distribution:

Hails from the Amazon and its main tributaries.

Size:

Up to 8". Most aquarium specimens will reach between 6-8" in length. Height can be equal to length.

Diet:

Naturally carnivores; will eat most foods offered, though they have a special penchant for worms (blackworms, bloodworms).

Water Temperature:

29-29C (82-84F).

Water Chemistry:

Very soft water (10-120 microsiemens).

pH:

5.5-6.5.

Life Span:

10-15 years.

Sexing:

Sexing Discus is a very uncertain practice. Males will usually develop somewhat of a nuchal (forehead) hump and can have longer pectoral fins, although this is not always the case. Mostly, sexing can only be 100% once you have a successfully breeding pair. Sometimes, two females will pair and take turns laying eggs. If there are 2 weeks or less between apparent spawns, there is a strong chance you have two females.

Breeding:

Most Discus seen in the hobby are captive-bred specimens. These fish are bred for their bright colors and unique patterns. There is an almost endless list of color variants available to hobbyists today. Discus are egg layers, often choosing a vertical surface to lay their eggs on (sometimes being the heater). A spawning cone or inverted flowerpots are used by many breeders as surfaces for the Discus to spawn on. The parents will mouth the eggs to keep them clean and free of debris. Discus are bred the world over, ranging from large hatcheries in Asia and South America to the United States.

Description:

The Discus is often referred to as "the King of the aquarium", and there is good reason for it. Few freshwater, and indeed few saltwater, can match their regal stature and array of possible color schemes. Discus come in graceful pastel browns, reds and greens to vibrant and neon blues, orange and yellow. Discus can be colored in a pair, one solid, or a palette of colors. Ideal body shape for Discus is a very tall, rounded figure. Idealists shy away from fish that are shaped like footballs or arrowheads, preferring the circular form. Discus can also be had in high-finned and high-bodied varieties. If you can imagine a color and characteristic, there is a good likelihood that someone out there breeds.

Requirements:

Discus, in nature, come from very soft, nutrient-poor waters. These areas have low pH values and very low nutrient concentrations. Many of the waters they come from are quite turbid, blocking sunlight from passing through the water and warding off any plant growth. Discus make their home in the tangles roots of submerged trees. The ideal Discus aquarium has soft, very clean water, with a pH of about 6.5 and subdued lighting. A slow flow of water movement is desirable. Although there are general rules of thumb for keeping Discus, none of them are perfect. For adult fish, there should be around 10 gallons of water per fish. Having been bred in captivity for so long, most Discus available in the hobby are highly adaptable to different aquarium conditions if acclimated properly. Once acclimation is complete, Discus are like most other fish; it is most important to keep your water clean and its chemistry constant. These fish can thrive in a high pH in hard water. In fact, many breeders will keep growing Discus in harder water since this tends to speed their growth as there are more nutrients biologically available to the fish. For growing Discus, water changes should be done at least every other day, as much as 50%. Serious breeders will routinely do 50-90% daily changes. For grown Discus in a display aquarium, weekly changes of 25% usually suffice. Fry should be fed 6-8 times per day with a high-quality variety of foods. Growing juveniles should be fed 3-5 times per day, and adults at least twice per day. Care should be taken when feeding live foods, as they can harbour parasites, which may infest your fish.

Behaviour:

Discus can be a rather shy and timid fish. If the fish are constantly hiding, this can be an indicator of poor water quality. With clean water and good husbandry, Discus can become very tame and trusting, often taking their food directly from their keeper's hand. They should not be housed with other fish that will harass or intimidate them, such as African Cichlids, Angelfish or any other larger, boisterous species. A single-species tank is ideal for Discus, though they can also be housed with smaller Tetras or Dwarf Cichlids.

Notes on selecting Discus:

In many countries, Discus are a huge industry. Their best stock is often kept for breeding or show purposes, with the inferior, unhealthy or poorly shaped Discus being sent elsewhere for sale. To be successful, locally bred Discus are always your best bet. Look for a fish that is active, not shy or timid, is eating well and whose eyes are not oversized for its body size. If you move your hand to the top of the tank, the fish should come swimming up, looking for food. If they don't, they may not be feeding. A Discus that has stopped eating is difficult to get started again.

Notes on wild-caught Discus:

Wild-caught Discus (as well as most other Discus you will acquire) will often have an internal worm infestation. A dose of praziquantal (available through veterinarians or certain brands of fish medication) will rid the fish of these worms, which will be passed through their ventral opening.

A special note on Angelfish and Discus:

Although these two fish are quite closely related, and have very similar requirements (they even look similar in body shape), they are NOT a good fish to be kept together. Angelfish are generally more aggressive than most Discus. Also, they often harbour internal parasites that show no effects on the Angelfish, but are easily caught by the Discus with disastrous results.

Photo Credit:

Photos supplied courtesy and ^© Verse914