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Discus – Symphysodon


Discus – Symphysodon

Cichlids are a very ancient and extensive classification of fishes dating back millions of years before, for example, dinosaurs. Cichlids probably originated around 550 million years ago (give or take a month or two 😀) and there are somewhere in the region of 2,000 to 3,000 different species, of which around 1,700 have been classified (at the time of writing).

Cichlids can make excellent community fish but you should take care because not all Cichlids are good community fish and may devastate an established aquarium, treating their tankmates as food, so before choosing a Cichlid, please ensure that you know whether or not your choice will be appropriate to your needs.

Is Discus (Symphysodon) a good community fish? Discus (Symphysodon) should be considered to be an excellent community fish assuming that the community is one of non-aggressive, non-predatory species. Discus (Symphysodon) is suitable for all community aquariums although it can be territorial, particularly during breeding. 

Key Facts about Discus (Symphysodon)

CategoryKey Facts
Common name(s)Discus Cichlid – also known as:
Pompadour Fish
Scientific nameSymphysodon
FamilyCichlidae
Originate fromWarm waters of the lower reaches of the Rio Negro, upper Uatumã, Nhamundá, Trombetas and Abacaxis Rivers in Brazil, in South America
Care requiredEasy to care for and very beautiful
TemperamentRelatively placid shoaling fish
Colour & FormAlmost circular body with very elegant finnage
LifespanUp to 10 years but could be 15 years
Adult size8 inches
DietHerbivorous in nature but captive-bred are omnivorous – eats Daphnia, Bloodworm, Tubifex worms, pellet and flake food in the aquarium.
Aquarium size48 inches in length or greater
Compatible withMost other Tetras, Barbs, Danios, Guppies and other livebearers, dwarf cichlids, smaller Gouramis, catfish and loaches that live in fairly neutral, soft water
Avoid keeping withLarge and/or aggressive species in too small an aquarium of known fin-nippers
BreedingEasy if you put the fish in the right environment.
Water temp82 – 86 Fahrenheit in nature – captive-bred are more tolerant
Water pH4.2 to 6.2 in nature – captive-bred are more tolerant
Water hardness (dGH or dH)1 to 4 dGH in nature – captive-bred are more tolerant

Origins of Discus (Symphysodon)

Discus (Symphysodon) – commonly known as the Red Discus or Heckel Discus –  is found in the soft, acidic, warm waters of the lower reaches of the Rio Negro, upper Uatumã, Nhamundá, Trombetas and Abacaxis Rivers in Brazil, in South America.

In addition to Discus (Symphysodon), there are two other species of Discus, each of which is found elsewhere. These species are:

  • Symphysodon aequifasciatus (Blue Discus or Brown Discus)
  • Symphysodon tarzoo (Green Discus)

More recently, selective, captive hybridization has produced an entire rainbow of Discus’ to the extent that you can pretty well choose whatever color you want.

Discus (Symphysodon) is usually found in nature in lakes, slow-flowing streams, on the margins of larger rivers, in marshland, in ponds and also in lakes but seldom, if ever, in stagnant water.

Basic Characteristics of Discus (Symphysodon)

Discus (Symphysodon) will grow up to around 8 inches in length and in height in the aquarium. In young fish, it is difficult to distinguish between the sexes so if you are purchasing young fish then buy half-a-dozen and you should have a mix of the sexes.

There are probably about as many opinions about distinguishing the sex of a Discus, even an adult Discus as there are articles about the Discus. In truth, in my experience, the only truly certain way of distinguishing between the sexes is when you observe a female laying her eggs and her mate fertilizing them.

The lifespan of Discus (Symphysodon) is around ten years or more but this can vary enormously depending on tank conditions and general health. The Discus (Symphysodon) can live for as long as fifteen years

Discus (Symphysodon) in nature prefers soft, acidic water with a pH of 4.2 to 6.2  and a temperature range between 82 and 86 degrees Fahrenheit and from 1 to 4 dGH.

Captive-bred Discus (Symphysodon) have, over time, become accustomed to living in fairly neutral water (from the faucet), at lower temperatures and a much wider tolerance in respect of water hardness.

As the Discus (Symphysodon) is quite a timid fish it is best not to keep it with aggressive species. That said, Discus (Symphysodon), being Cichlids, will defend themselves and, especially in respect of smaller fin-nippers, they are likely to retaliate with prejudice.

Discus (Symphysodon) will generally dwell throughout the water column and will enjoy a fine substrate. In nature, it is primarily herbivorous but will consume invertebrates including bloodworm. I have observed Discus (Symphysodon) rotating almost vertically downwards to enjoy a meal of live bloodworm on the substrate. Again, because you are more likely to have captive-bred Discus (Symphysodon) than wild Discus (Symphysodon) then you are likely to find that a general, mixed diet will be perfectly adequate.

The physical appearance of Discus (Symphysodon)

  • The Discus is almost circular in profile and, like the Angelfish, it is very slender when viewed from the front, back, top or bottom. Unlike the Angelfish, with the exception of the ventral fins, the fins of the Discus are far more compact.
  • Overall, the base-color of the Red discus is white or silvery. Its face is yellow/orange with a distinctive, dark orange eye around the black pupil and the face shows through some of the white base-color as marbling.
  • This yellow/orange coloring presents itself once more in the caudal peduncle and, to a lesser extent, around the upper, rear half of the body. 
  • The main body is a mixture of the base-color marbled with an orange/red pattern, which extends into the dorsal, ventral and anal fins. 
  • The pectoral and caudal fins tend to be clear (hyaline).

Please note that different color variants will breed together, creating offspring with an increasingly diverse range of colors over several generations.

The Discus (Symphysodon) is a larger Cichlid. It has extended pectoral fins. It is advised not to include this species with known fin-nippers.

The living environment for Discus (Symphysodon)

Discus (Symphysodon) enjoys being in the shade so a well-planted tank is beneficial to it.

Discus (Symphysodon) will appreciate floating leaves and pretty well any broadleaf will assist the condition of the tank, as not only do such leaves provide shade but also, as they decompose, they provide infusoria for any fry in the tank. This also helps adults to determine that breeding conditions are good because they will appreciate the fact that there is a ready source of food for newly-hatched fry.

Note that Discus (Symphysodon) will not generally mate for life but they will make good parents for the brood that they are rearing. I should, in fairness, state that there are some who hold the opinion that Discus (Symphysodon) do mate for life but that has not been my experience.

It is recommended that Discus (Symphysodon) are kept as a small shoal. The male, in particular, can be territorial but setting up the tank so that sightlines are broken up will mitigate the risks of territorial behavior in general. When purchasing Discus (Symphysodon) it is generally recommended to buy around six fish. It will be impossible to sex the fish when purchasing them as immature specimens but, in due course, they will find their own mate and are, from that point, generally biparental for the purposes of rearing a specific brood.

Having a clear, broad area of a fine substrate will protect the elegant finnage of your Discus (Symphysodon).

Overall, Discus (Symphysodon) are the most attractive and most elegant addition to your aquarium and, for many years, have been referred to as the “King of Fish” – not sure how the females feel about this 😁 .

The diet of Discus (Symphysodon)

Discus (Symphysodon) is primarily herbivorous in nature but most captive-bred specimens will enjoy much the same diet as most other aquarium fishes. In the aquarium a diet of live or frozen Artemia, Bloodworm and Daphnia is recommended and Discus (Symphysodon)  will readily eat pelleted food and flake food. 

Sexual differences in Discus (Symphysodon)

It is reasonably easy to distinguish the sex of the adult Discus (Symphysodon) only when the female is laying eggs and the male is fertilizing them. Otherwise, sexing even adult Discus (Symphysodon) is nigh on impossible, despite the claims of others.

Aquarium size for Discus (Symphysodon) 

It is generally advised that the minimum tank size for Discus (Symphysodon)  should be one of at least 48 inches in length or more due to the fact that a shoal of around six per species should be maintained and the adult fish will be around six inches long. This will enable your small shoal to move around freely. A smaller tank will be too restrictive (unless it is a breeding tank) and the fish will suffer as a result whilst a larger tank is always to be recommended.

There is a predominance of so-called “Nano tanks” available but, being old-fashioned, I prefer my fishes to live in an environment which, at least, attempts to mimic nature, rather than living in what I would liken to a piscine prison cell. The tank should be well-planted but with clear areas where the fish can swim freely. The water should have a certain amount of movement, as Discus (Symphysodon) enjoy a flow of water.

Discus (Symphysodon) – Videos

How to keep Discus (video) – 1hr 20min

How to breed discus (video) – 29mins

Are you keeping tropical fish as a hobbyist or as a breeder?

This is a question too often ignored in my humble opinion. If you are a breeder (either commercially or as a hobbyist who gives away young fish to other hobbyists) then you will need the resources to move fish into breeding tanks in order to maximize the yield of fry that will grow up either for sale or to give them away.

If you are keeping fish for the joy of observing them in something resembling a natural habitat then you may feel that it is appropriate to allow nature to take its course and, as and when different species breed, then many of the eggs (and surviving fry) will be eaten either by their parents or by other fish in your aquarium. This is the natural order of things because this is what will happen in nature. The fittest may well survive to reach adulthood.

Ultimately, the choice is yours to make.

How does Discus (Symphysodon) breed?

In total, the female Discus (Symphysodon) could lay several hundred eggs during a single spawning. The spawning can be repeated every week for up to fifteen weeks and there may be two annual spawning seasons.

If you are breeding Discus (Symphysodon) using a breeding cone or on a slate then the adults will fastidiously clean the surface on which the female will lay her eggs.

At around 82 degrees Fahrenheit, the eggs will hatch in around two days and the fry will become free-swimming after another two days.

The young Discus (Symphysodon) will feed on mucus excreted through the skin of its parents and, in addition to this being of nutritional value, it also promotes the immune system of the fry. As the fry grow, the parents will distance themselves from the fry in order that the fry will learn to fend for themselves and to protect the scales of the parents from the ravages of rapidly growing, hungry fry.

It is generally true that Discus (Symphysodon) make good parents and will not prey on their own young.

The female Discus (Symphysodon) will generally lay her eggs in a line along a slate or breeding cone. The male will then swim over that line of eggs and fertilize them. This process will then be repeated until the female has laid all of her eggs and the male has fertilized then and the result will be several rows of fertilized eggs.

The Discus (Symphysodon) takes responsibility for post-spawning care and may become extremely aggressive if it feels that the brood is threatened. For this reason, if possible, a breeding tank is recommended.

It takes around two days for the eggs to hatch, depending on the water conditions and temperature and a further two days or so for the yolk sacs to be depleted and the fry to become free-swimming.

In a well-planted aquarium, the Cichlid will often spawn in the community tank and at least some of the fittest fry will survive to adulthood.

In a breeding tank, it is always a good idea to include a few aquatic shrimp, as they will consume any unfertilized or dead eggs but won’t tend to predate on viable eggs.

Breeding tank for Discus (Symphysodon)

You should prepare a tank of around thirty gallons in size with mature, soft, flowing water. The water should have a low level of light and broad-leaved plants together with some well-cleaned slate or a breeding cone upon which the female will lay her adhesive eggs. It is recommended that the substrate (if any) consists of a fine substrate (sand) without sharp edges. 

Arrange your tank heating so that you can slowly remove up to half of the tank water and then replace it with collected rainwater (slightly cooler than the aquarium water – but not so much that White Spot could result) and repeat this daily until the Cichlids spawn. This water and temperature change will encourage spawning, as it mimics nature.

Cichlids prefer to spawn where the water is flowing so a decent pump is required to synthesize that flow.

Feed up your Cichlids on bloodworm, which will sink to the bottom and burrow into the substrate (if any). Your Cichlid will love rooting out the bloodworm and it can help to trigger spawning.

You may also wish to introduce baby brine shrimp, mosquito larvae or tubifex worms as an inducement to reproduction and live food will be very much appreciated. This will also tend to divert the attention of the Discus (Symphysodon) from preying on their own eggs and fry though cannibalism is not characteristic of Discus (Symphysodon).

Reduce the water movement by turning down the pump once the eggs are laid – only regular aeration is now required. Keep the lights very low because eggs and fry can be particularly sensitive to the light.

The eggs will hatch typically in two days depending on tank temperature and conditions and the fry will become free-swimming after around two days after hatching. 

Keep the tank dimly lit for the first week or so then gradually increase the lighting. Bear in mind that the eggs and fry of a fish will initially be tiny so you may need to use a magnifier “app” on your smartphone or a macro lens to see anything at all. A collection of eggs is generally easy to spot, as they look like a collection of tiny, brown pearls.

The newly hatched fry will feed firstly on their yolk sac and remain static but, once free-swimming, can be fed infusoria and will also thrive on egg yolk during the first two to four weeks in addition to them feeding from the mucus on the skin of their parents. 

Once the fry are free-swimming and their yolk sacs are depleted, then add baby brine shrimp and/or white worms. Once the fry are sufficient in size not to be treated as a snack then they can be introduced into the community tank where they will join the existing shoal. Before moving the adolescent fish into the community tank ensure that you have balanced the water temperatures to mitigate the risk of White Spot or other diseases being triggered.

Unless you are breeding commercially, you may wish to consider moving the fry into the community tank sooner rather than later. It may seem harsh but the adult fish in the tank will deal with any fry that are unlikely to survive to adulthood in the wild and you are synthesizing, to the best of your ability, a wild environment. The fittest fry will probably survive whilst the rest will be dealt with by the community.

Should your Discus (Symphysodon) have a special diet for breeding?

Adult Cichlids don’t need any particular inducement to breed. That said, it has been suggested that adding tubifex, bloodworm, or mosquito larva may encourage them, presumably because the addition of a new food may “fool” the fish into thinking that it is breeding time. From my own experience, I would always recommend keeping all of your fish in the best possible condition at all times, as this is good for the wellbeing of your fish.

Mike Wheeler

I started keeping freshwater tropical fish in 1972 and it has been something of a passion ever since. In this website, my aim is to build up an everyman's guide to help the everyday aquarist get the best from this inspiring and entertaining hobby.

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