Symphysodon, colloquially known as discus fish, is a genus of cichlids native to the Amazon river basin in South America. Due to their distinctive shape and bright colors, discus fish are popular as freshwater aquarium fish, and their aquaculture in several countries in Asia is a major industry.
Table Of Content
- 1 Taxonomy 🐠
- 2 Discus Fish: Main Characteristics
- 3 Main Species. 🐠
- 4 Discus Fish: Distribution and Habitat 🐠
- 5 Discus Fish: Feeding Habits 🐠
- 6 How Discus Fish Reproduce? 🐠
- 7 Discus Fish: Behavior 🐠
- 8 Life expectancy 🐠
- 9 Diseases 🐠
- 10 Discus Fish in Captivity 🐠
- 11 Breeding Discus fish 🐠
- 12 Commercialization of Discus Fish 🐠
Kingdom: Animalia ..Phylum: Chordata Class: Actinopterygii Order: Cichliformes Family: CichlidaeGenus: Symphysodon Heckel,
Discus Fish: Main Characteristics
Discus fish have different characteristics depending on the species we are talking about. However there are some common characteristics for all that we will mention below.
This species is characterized by having a tall body of round shape, and laterally compressed.
Their dorsal fin covers the entire upper part of the body until it reaches the caudal fin.
This fin is shaped like a shovel and together with the pectoral fins it performs propulsion functions.
Discus fish also have a dorsal fin that extends in the lower part, from the caudal fin to the ventral fins which are are very elongated and triangular in shape.
There are no major differences between the sexes and can only be seen from the time they reach adulthood.
Sexual dimorphism: Nonexistent, they only differ sexually at the time of birth, when their genital organs protrude since the male sperm duct is smaller and pointed and the ovipositor is a thicker tube.
In this species the intense red color of its eyes stands out as well as its nine dark vertical stripes that are very striking. The appearance depends on the mood of the fish and therefore are not always visible.
The lines run all over their body; the first one crosses their eyes vertically while the last one is located at the birth of the caudal fin.
Main Species. 🐠
Let’s meet the main species within this family
(Symphysodon aequifasciatus). Blue discus or brown discus,
As the name implies, this fish has a rounded shape and a crushed body. Symphysodon aequifasciatus measures around 15 cm in diameter.
Its movement is carried out through their very well developed pectoral fins and when they need to speed either for fights or to flee, they also use their powerful caudal fin.
The dorsal and anal fins cover both the upper part and bottom of the fish helping to give the disk shape. Finally but not less important, discus fish also have quite long -triangular shaped ventral fins.
There are 4 great varieties:
✔️ S. discus (heckel discs), which have the first, third and even more the fifth stress lines or bands very accentuated and light brown in color.
✔️ S. aequifasciatus haraldi: Red Spotted Discus. (some say they the green discs also enter in this classification, but it is not yet clear) they have no differentiation in the Stress lines of intense blue color and are the easiest to take care of in captivity. The red spotted discus are also the predecessors of the turquoise.
✔️ S. aequifasciatus axelrodi: Brown discs, with some bluish spots (which leads to think of their mixture at some point with the haraldi) usually have a line that borders the anal and dorsal fins with a more reddish hue.
✔️ S. aequifasciatus aequifasciatus: there are those who believe that this species is very similar to the haraldi, but the stress lines are more disguised and their predominant color is green.
Hybrid Discus Fish 🐠
✔️ Diamond blue disk : This species was generated in Malaysia. They come from the blue turquoise discus fish
✔️ Red turquoise disk: It comes from mixing blue and green discs. It was named in Germany.
✔️ Pigeon blood discus : This species was Developed in Thailand in 1991.
✔️ Leopard skin discus : This is a Selective breeding from green discs with red spots.
✔️ Snake skin discus :Its exact origin is unknown although everything points to the blue turquoise, like its brother Blue Diamond.
✔️ Leopard snakeskin discus: It was discovered in 1997. It’s a Crossings between leopard skin and snake skin.
✔️ Snow white discus : This is a native species to Malaysia. It comes from brown disc crosses,
✔️ Blue Turquise Discus- Fish: This species is called Jack in the United States. it’s a mix of selective blue and green discs.
Let’s meet them properly
Discus Fish: Distribution and Habitat 🐠
Discus Fish are native from South America specifically from Brazil and Peru. They are very common at the Amazon river’s basins and water lakes without much activity. Discus fish usually prefer warm temperatures, typical of this tropical zone.
During flooding times the river drags the vegetation into its waters, creating a large amount of organic material that decomposes over time.
This event conditions the variables to which the disk fish is accustomed, such as an acidic pH (between 4 and 6) and practically zero water hardness.
In this last aspect, the degree of acidity of the water in the natural environment, favors the low presence of bacteria and parasites that can infect this species,hence the importance of maintaining the appropriate parameters in our aquarium, given the obvious vulnerability of these species.
Let’s keep learning about these wonderful creatures….
Discus Fish: Feeding Habits 🐠
The key in this aspect is undoubtedly the balance that we can maintain in the diet of the discus fish and the ability to combine live foods, such as mosquito larvae or artemia, with scales, tubifex and some vegetables.
Among the experienced breeders, homemade porridge, consisting of liver and heart of chicken, egg, banana, carrots, etc. is commonly used as food.
As for the feeding frequency, our recommendation is that it be twice a day, always in small portions (keep in mind that fish are more likely to die from overfeeding) and ensuring that the diet contains proteins and vitamins, so necessary for the good development of our discus fish.
How Discus Fish Reproduce? 🐠
When the time comes to reproduce that goes from October to April, the male discus fish begin the courtship ritual towards the female.
For this they give her a little walk and then show,( both the female and the male), their beautiful colors. After the process they look for a suitable place for laying.
The first eggs can be eaten by the parents, but we should not worry about it, because over time they will gain confidence and end up making a final laying.
Within a few days, we can enjoy the fry swimming fully through the aquarium and feeding on the mucous secreted in the skin of their parents. Over time, we can start by introducing artemia and as the days go by, bigger foods.
Between the months of October and April, the courtship and gestation stages of discus fish take place
The ritual begins with a couple’s swim walk throughout the aquarium.
Then, the exhibition of colors occurs where each specimen makes finery of its attributes, and when finished, they look for the ideal place for the laying.. Some people tend to leave the couple completely alone in the aquarium.
Discus Fish: Behavior 🐠
These fish are gregarious, that is to say that they live in groups and are managed through a hierarchy. Within these groups, there is always the dominant male, although sometimes it can also be a couple.
The leaders mark their territory and feed first while the other fish are kept away.
It’s also important to mention that discus fish are very calm but territorial, behavior that is accentuated during breeding season.
The hierarchy is very strong in the group, and it’s common that there are fights between the members for the high hierarchical position.
They can live peacefully with other fish, however, if they are larger, the Disc Fish will live in fear and hidden.
Life expectancy 🐠
Discus fish live around twelve years when in captivity although it has been known of species that have reached fourteen years.
This life expectancy can be affected by different diseases apart from their natural predators such as piranha in their natural habitat.
There are various diseases that usually affect discus fish. The first one is Hexamitosis or commonly called Discus disease which is produced by a flagellated protozoan known by its scientific name Hexamita symphysodoni. This ectoparasite is pear-shaped and can be easily observed in a two-core microscope.
The characteristic symptoms of this disease are: weight loss, isolation and loss of appetite.
They also usually make strange movements such as turns and their colors go out. As the disease progresses, ulcers and holes begin to appear in the head of the fish and in the lateral line but to a lesser extent.
This disease is caused by the lack of hygiene in the aquarium and a poor diet low in nutrients.
The parasite affects the wild Discus Fish in its intestine and gradually weakens it. It spreads through the bloodstream and affects important organs such as the intestine and the liver causing co-management and death of the fish.
The parasite found in the intestine goes out of the fish’s feces outside and contaminates the aquarium water and in this way transmits the disease to the other fish.
For its treatment it’s necessary to detect it quickly since if it’s not it will be highly fatal.
The treatment should be based on antibiotics that possess Metronidazole and one gram per 100 liters of water should be added. Commercial medicines based on malachite green compound can also be supplied.
There are also bacterial diseases that are difficult to counteract, such as Aeromonas conditions, which are quite common in the discs, especially in the specimens that travel long distances.
Its cause is due more to the handling of the fish at the time of its commercialization than to sanitary reasons in the hatchery. In Argentina there is a tradition to treat this disease in which sulfa such as Bactrim is used although the results are not always satisfactory.
This happens since the sulfa drugs take to be assimilated by osmosis and there are cases where the disease is already very advanced. We also have cases where, due to loss of appetite, fish do not ingest such treatment.
The treatment of this disease should be based on prevention and when it should be noted that Enrofloxaxin can be used, which is a fourth generation antibiotic that has demonstrated some effectiveness.
It’s enough to apply one milliliter for every 50 liters of water and if it’s observed that the attack is strong it’s repeated every 48 hours until you see improvement, but its operation is not guaranteed.
Let us learn
Discus Fish in Captivity 🐠
Let’s learn about having these little angles in our fish tank
The aquarium required to enjoy discus fish must have a minimum capacity of 300 liters.
The constant water temperature should be 28º and it’s very important to emphasize that lower ranges of 26º tend to get them sick.
The pH must be 6, and the hardness index, that is the Gh, must be 5, which corresponds to soft water.
The discus fish is native to the Amazon River. Its habitat is slow, somewhat murky waters and backwaters.
Piranhas proliferate in this type of water and discus fish require dense underwater vegetation to protect themselves from such voracious creatures. For this reason, the aquarium must have appropriate plants.
Floating plants like Salvinia or Pistia type must be placed on the surface, whose function will be to dampen the fluorescent light that can dislodge disco fish. In the background, the recommended plants will be Ambulias, Anubias, and Echinodorus.
The sand must be adorned with «Chinese», that is, small stones with the edges rounded by the abrasion of the river current. Trunks without sharp parts are an excellent idea to complete the decoration.
There should be enough free space in the aquarium for the discus fish to swim easily.
Complementary fish 🐠
Discus fish, as the vast majority of cichlids, are aggressive towards fish of the same species . However, while they are small they can live with other smaller fish so that the aquarium does not look so empty.
The tetra red nose, neon, cardinal and tetra phantom in small quantities may live with these striking creatures.
As bottom fish, plecos and corydoras are suitable for this type of aquarium.
We invite you to read our article white spotted cichlids to learn about other species of cichlid fish
The Dominant Discus fish 🐠
Disco fish are aggressive fish with each other. There is always one that will be erected in the dominant fish that will have its own territory and will be the first to eat. A 300-liter aquarium can house three specimens of discus fish.
But this small number has a danger: if the dominant male is also joined by a dominant female, the third specimen will have serious problems and may even die from the stress caused by the fierce couple.
For this reason it’s advisable to increase the inhabitants of the aquarium by one or two more specimens of discus fish.
In this way, the pressure and the burden will be diluted a little. If this is done, it must be taken into account that each new discus fish will require an additional 100 liters.
Feeding Discus Fish 🐠
Without a doubt, one of the fundamental pillars of the care of discus fish is food.
In aquarium shops they sell specific food for discus fish, both live (tubifex), and in scales.
Your veterinarian should advise you on the most suitable types of food for your discus fish.
It’s convenient to feed them twice a day, varying the food so that your diet is balanced. In addition, it’s recommended that they fast Once a week
Aquarium maintenance 🐠
In order to offer our discus fish the best care, we must take into account the following indications:
✔️ Every day the temperature, acidity and hardness of the aquarium water will be checked, immediately correcting any observed deviations.
✔️ Weekly: 10% of the water will be partially changed to control the nitrate levels and keep them low.
This is one of the most important points to successfully keep these wild disc fish.
Most of the sick wild fish we commonly encounter are not properly quarantined or not quarantined. There are three stages to proper quarantine.
This happens when these fish are caught in the Amazon. It’s the responsibility of the exporter to ensure that the fish is not exported immediately.
A good exporter will often take the fish caught on his farm and take care of him to recover his normal health.
Unfortunately, most exporters do not usually do this practice, so the specimens that arrive in various parts of the world have not been properly fed and are somewhat weak and sometimes sick.
When the wild discus fish arrives at the importer / farm site They must remain in quarantine for a minimum of three weeks which is a quite acceptable period of time for them to adapt to their new environment.
This is the stage that most fans tend to ignore. When these fish are purchased from the retailer, it’s recommended that the hobbyist keep them in quarantine for another 4-5 weeks before adding them to the existing aquarium. It’s very advisable not to mix domestic and wild strains immediately.
Common problems caused by having less than this amount in the aquarium are harassment, loss of appetite and stress. This is very bad, so keep this point in mind. We invite you to read our article fish for fish tanks for a very comprehensive explanation about fish tanks.
Let’s learn more about this topic
Breeding Discus fish 🐠
Since discus fish (Symphysodon) prefers to choose its own partners, aquarists who expect to raise discus fish generally buy several specimens (5-10) at an early age.
When it’s seen that two fish are paired, the other fish should be moved to another aquarium..
Note: If you are lucky enough to have a local store that is dedicated or specializes in discus fish, the owner can allow you to observe the fish for a while and find A couple in the group.
If the store allows you to do this, you have found a real friend, sponsor that store, this will be your favorite place where you will buy disco fish.
How to differentiate male and female discus?
It’s almost impossible to distinguish male disc fish from females with the naked eye. As the spawning time approaches, the female’s abdomen enlarges slightly due to the eggs.
A few days before she lays her eggs, the female develops a short tube or ovipositor, just in front of her anal fin.
In most aspects the reproduction of discus fish is very similar to that of angel fish. .
The eggs hatch in around 3 or 4 days, during which the parents keep the eggs, fan them with their fins and clean them with their mouths, cleaning them and protecting them from fungi or foreign organisms that may fall on them.
At first, juvenile discus fish are tiny, splinter-shaped and remain almost motionless at the spawning site, unless parents move them to a new place, which they seem to do quite frequently.
This is where most parenting attempts have failed, but why? 🐠
Approximately 4 days after hatching, young discus fish become free swimmers.It’s here that most attempts to reproduce disc fish failed in the past.
Before we knew how this amazing and unique fish had adapted in the wild to raise their young, the breeders removed the parents from the aquarium, as they would with the other types of fish, to prevent the parents from eating them.
However, the fish fry did not eat and began to die almost as soon as the parents were removed.
They tried to give many different types of food for breeding, but at most 1-6 were all that could be saved from lots of up to 200 fry.
Parents are necessary for the development of discus fish 🐠
Several aquarists made a truly amazing discovery. They decided to leave parents with newborn pups, since discus fish are good parents and are absolutely necessary for the development of the offspring.
They discovered that the baby discus fish eats something from the sides of its parents (silt or secretions), as a puppy would with its mother.
In addition, they found that by removing parents discs from the offspring, it was inevitable to starve and kill the offspring.
One of the first to observe the feeding of their parents’ baby disc fish was Gene Woldsheimer, a talented photographer from California, famous in those days for his cover photos in The Aquarium magazine:
Subsequent studies by scientists showed that there are cells or glands that produce special foods in the parents’ skin.
When babies reach the age of swimming freely, they cling to the parents’ side, feeding while they cling.
When one of the parents gets tired of the babies, they shake and all the babies pass to the other parent.
For several weeks the young continue to receive food from the parents. Gradually, they become less and less dependent on parents, until finally, they are completely alone. Baby discus fish can be almost half an inch long before they become completely independent.
The young discus fish gradually looks like its parents. During the first months, they are elongated, like most cichlids. But when the fish’s body reaches the size of a dime, it’s almost as rounded as the adult.
Technical data for succesfully reproducing discus fish 🐠
Today there are many shortcuts to reproduce discus fish, and we encourage you to try some of them. First we must know the natural waters of the discus fish to understand the perfect aquarium environment for a breeding pair.
✔️ In nature, discus fish can only tolerate small changes in their environment. Their natural water habitats have extremely low amounts of electrolytes, with a total hardness of less than 1 dH.
✔️ The high amount of humic acids and tannins means that there is a low amount of bacteria and fungi. The pH value is approximately 6, so the water reacts slightly acidic.
✔️ To take care of disc fish successfully, water must be prepared as necessary (reverse osmosis) and must also be monitored at intervals of 2 to 3 weeks; Otherwise, the electrolyte content in the aquarium will rise too high.
✔️ Apart from reducing water hardness, it’s especially necessary to achieve the properties of dystrophic waters by adding humic acids and tannins, either by periodic filtration or by adding extracts.
By these methods, the necessary slightly acidic pH value will also be reached.
✔️ It’s not advisable to increase acidity with phosphoric acid due to the sensitivity of the disk fish to that chemical. In addition, the damping properties of extremely soft water are mild and will counteract its effect.
✔️ An aquarium containing discus fish should always be very large so that specimens have enough space to swim and spin freely without any impediment.
✔️ The temperature must be constant, but it can be maintained anywhere between 82F and 86F, provided that its heating element is large and stable enough to keep the temperature at a temperature without fluctuations.
✔️ To induce reproduction, it’s suggested to raise the temperature from 82 ° F to 86 ° F, only as a last resort, when dealing with a pair of persistent discs.
✔️ Large aquatic plants such as the Amazon sword in many of its varieties are a favorite of this species. They also add stumps of leached roots that will create the necessary cover and lodging places.
✔️ To really delve into the path of nature, let’s take a look at all-natural food to stimulate reproduction activities.
Feed specimens with a varied diet, but never overfeed. Overfeeding fools water, something they can never tolerate.
✔️ Use mosquito larvae and crustaceans of appropriate size for feeding. Disc fish are adept at collecting live food from the substrate, however, do not feed them with Tubifex or Red Mosquito larvae.
✔️ These 2 types of animals live in the mud of heavily polluted waters and, therefore, contain many pathogens and toxins, to which the discus fish is sensitive.
✔️ It’s very important to remember that if it’s kept in inadequate conditions, the disk fish reacts very quickly: they reject food, the digestive system is disturbed (white viscous feces) and they are attacked by the dreaded «disk fish disease» and they are also susceptible to «Head hole» disease
✔️ Although discus fish are very peaceful with other fish, they should be kept exclusively in an aquarium of unique species if you want them to reproduce. They do not have to be bothered by other fish.
let’s watch how they feed baby specimens
Commercialization of Discus Fish 🐠
When we are going to acquire the wild Amazonian Disc Fish regardless of the variety we want we must take into account that the wild variety circles are very expensive therefore it’s important that we make the best possible investment and be careful that they do not sell us a specimen that we do not want.
It’s a bit difficult to find good specimens because the best specimens go to the Japanese market.
In the rest of the world what they have exceptional specimens that are selected in contests and exhibitions are high person purchasing powers that are willing to pay large amounts of money.
Also in Spain there is currently no great fondness for these fish on the other hand other European countries such as France, Italy and Germany among others the fondness for the wild is very widespread and is growing at a good pace.
These fish to be imported from South America imply an extra cost very high and also its mortality during transport is high.
Merchants prefer to bring low quality fish that allows them to reach a wider market, customers with low and medium purchasing power. As a summary of all the above, we have several recommendations if we want quality circles.
First we must make the commercial transaction directly with Brazilian suppliers, taking into account the very high size and risks that may arise and if this is possible because.
If these people manage to bring the fish, it’s necessary to bring a large amount of fish, so if you meet with people who are also interested in this fish, it would be very useful.
Another option would be to talk with companies that import the wild Amazonian Disc Fish from your country and let them know your wishes to see if it’s possible to import the fish along with those of lower quality.
The selection of these fish is usually done through photographs provided by the importer from Brazil and then there is a second filter that is mostly done by videoconference to visualize the live specimen, this is done out of the water on a flat surface with its flaps deployed .
Let’s have a final look of them