Everything About Discus Fish: Types, Personality, Lifespan, Nutrition

Discus fish belong to the Cichlidae family, one of the largest groups of freshwater fish. These fish are part of the Symphysodon genus and can be divided into three species. The first species is Symphysodon aequifasciatus, also called blue/brown or common discus.

The Heckel discus fish, or Symphysodon discus fish, is the second species of discus fish, named after Dr. Johann Jakob Heckel, an Australian zoologist and ichthyologist. Dr. Heckel is best known for his book The Freshwater Fishes of the Austrian Danubian Monarchy, but it is also credited with being among the first to describe the variants of the discus fish since 1840.

The third species of discus fish, called Symphysodon tarzoo, has only been recognized as a separate species in the last century. Previously, it was believed that Symphysodon aequifasciatus and Symphysodon discus, both native to the central/eastern waters of the Amazon, were the only two species of existing disco fish.

However, new evidence suggests that these two species have relatively few genetic differences and probably belong to a single variable species. Symphysodon tarzoo was first identified in 1959 by Earl Lyons, an American aquarist.

In an article published in 1969 in the Journal of Fish Biology, the Swedish ichthyologist Sven O. Kullander and his associates recognized the color differences between the other two disk species and the Symphysodon tarsus.

Kullander attributes these morphological differences to the genetic isolation of Symphysodon tarzoo, a native of the western Amazon, of its central/eastern Amazonian relatives.

Types Of Discus Fish

1. Red Tropical Symphysodon Discus Or Heckel Discus Fish

The Heckel Discus, or Symphysodon discus, is native to the central/eastern region of the Amazon, originating from the Rio Negro in Brazil. This type of discus fish is easily distinguished in that of the nine bars running vertically across the body, the first, fifth and ninth are bold in comparison to those exhibited by other species.

discus fishThe first of these bold stripes run vertically through the eye and the ninth through the caudal fin. The fifth and most prominent stripe runs vertically down the center of the body. This stripe is noticeably wider than the other stripes in mature adults of the species.

The Heckel Discus is also known as the Pompadour Fish and comes in two varieties: the Red Heckel Discus and the Pineapple Discus.

The body of the Red Heckel is reddish-brown, marked with blue or turquoise veins and red coloration on the edges of the fins. This type of discus fish is widely considered one of the most beautiful freshwater fish. The Pineapple Discus, a native of the Abacaxis River to the south of the Amazon, exhibits a pastel and faded coloration with a broad central band.

Both variants of Heckel Discus are relatively peaceful and shy, although they prefer to stay in pairs or groups with other albums. These fish require a slightly planted aquarium with dim light and soft substrate, an environment that mimics the calm waters of their home birth in the Amazon.

The Heckel Discus is notoriously difficult to maintain in the domestic aquarium because it is more delicate than other species: these fish have specific requirements for tank conditions and are particularly sensitive to water changes and susceptible to disease.

2. Aequifasciatus Symphysodon Or Common Discus Fish

This discus fish group can be divided into three subspecies according to the color: brown, blue and green.

The brown discus (Symphysodon aequifasciatus axelrodi) was once one of the most popular discus fish because it can be easier to maintain compared to other discus variants in the domestic aquarium. This subspecies varies in color from light brown to reddish-brown similar to rust. Like all discus, the brown discus fish has a series of vertical stripes that cross its body and these stripes are more noticeable around the fins.

discus fishThe blue discus (Symphysodon aequifasciatus haraldi) generally exhibits a dark blue or violet-brown coloration in their bodies. The blue discus is easily recognized by the blue longitudinal stripes and dark bands that extend horizontally along the body. Some variants such as cobalt blue discus have a metallic luster, while others, such as the Royal Blue discus, show a mixture of striking colors such as blue and yellow.

This subspecies of discus fish can be moderately difficult to maintain in the domestic aquarium due to its nutritional needs and water quality requirements.

Like all discus, blue discus are largely carnivorous and require a varied diet of live, frozen and granulated foods. In addition to its strict nutritional needs, Blue Discus requires mild and acidic water similar to its native habitat in South America.

The final subspecies of common Discus  (Symphysodon aequifasciatus aequifasciatus) or the green discus fish. This group of discus fish has a wide variety of colorations ranging from solid green to greenish-yellow and brown.

Although they show a wide range of colors, the intensity of their coloration is often quite smooth. In the domestic aquarium, these fish can be very difficult to maintain due to their specific requirements for water conditions.

3. Symphysodon Tarzoo (Tefé Discus Fish)

This species of fish is not, in fact, a new species, but one that has been part of the aquarium trade for years under the name of Tefé Discus. However, in recent years, these fish have been recognized as a separate species from the central/eastern species of the Symphysodon aequifasciatus and Symphysodon discus.

Symphysodon tarzoo was first studied during the 1950s, but because there was an insufficient number of specimens available for the study, the species was placed synonymy.

Upon re-studying, the study, Kullander and his associates Ready and Ferreira determined that differences in mitochondrial DNA and morphology between specimens taken from the eastern and western regions of the Amazon were sufficient to label Symphysodon tarzoo as a separate species.

This species can be identified by red spots on the anal fin and body.

Features And Personality Of Discus Fish

Discus fish belong to the Cichlidae family and the genus Symphysodon. The three natural species of discus fish have the scientific names Symphysodon discus, Symphysodon aequifasciatus and Symphysodon tarzoo.

In addition to these natural species, there are a variety of man-made discus species produced through selective breeding and natural mutations. Although discus fish are a type of cichlid, they are very different from many members of this family of fish.

Discus fish are more similar in appearance to angelfish that belong to the genus Pterophyllum. Because angelfish also originate in tropical regions of South America, they have similar tank requirements to those of discus fish.

The discus fish and the angelfish also exhibit round, laterally compressed bodies, often marked with longitudinal stripes.

Pet stores and breeders often sell juvenile discus fish when they reach the approximate size of half a dollar. Although their adult size may vary slightly depending on the species, most mature discus fish grow between 8 and 10 inches long.

The average weight of most tropical fish species can be calculated at a rate of 10 grams per cubic inch. A mature discus fish could exhibit measures 6 by 4 by .5 inches, putting its weight around 120 grams.

However, because a large part of the size of a discus fish can be attributed to the fins, its weight could be estimated more accurately around 75 grams.

The main distinguishing feature to which the popularity of the discus fish can be attributed is its vibrant coloration. Although many of the “natural” species of discus fish are somewhat soft in color, the man-made specimens show a wide variety of colors and patterns ranging from bright blue and bright yellow to deep reds and striking greens.

In addition to their beautiful coloration, aquarium fans appreciate the calm elegance of these fish. Discus fish are generally calm, peaceful and exhibit a dedication to their offspring unparalleled by most tropical freshwater species. Unlike many species that eat their young, discus fish really take care of their fry until two weeks after they are born.

All species belonging to the Cichlidae family have flat bodies. Discus fish, however, exhibit the most laterally compressed bodies of any type of cichlid. The round shape of the body, similar to a discus, is another unique feature that differentiates them from other cichlids.

This form is particularly suitable for the native environment of discus fish where they should be able to navigate in thick stands of underwater vegetation and submerged roots with relative ease.

Most discus species grow to be quite large, measuring between 20 and 25 cm (8-10 inches) at maturity. Although most disc varieties exhibit a similar shape and size, there are innumerable color variations.

The bodies of discus fish can be green, brown, red or blue, offset by dark or colored strips or veining. All discus fish has 9 vertical stripes on their bodies, although the intensity and thickness of these stripes may vary depending on the type of discus fish.

In some species such as Heckel Discus, several of these stripes are in bold, but in other species, they may be barely noticeable.

Discus Fish Lifespan

Some species of discus fish are notoriously difficult to maintain in the domestic aquarium, but under the right conditions, a healthy discus fish can live 10 years or more.

To maximize the life spam of discus fish, it is important to recreate the natural environment of discus fish as closely as possible in the domestic aquarium.

In addition to satisfying the tank requirements and water conditions preferred by discus fish, a healthy and varied diet can also greatly affect the longevity of these fish.

If the nutritional needs of a discus fish are adequately met, it will be more likely to live a long and healthy life in captivity.

Behavior And Aggression Of Discus Fish

While many species belonging to the cichlid family are territorial and aggressive, discus fish are generally peaceful and social fish. Discus fish are schooling fish and, as such, prefer to stay in groups of three or more.

discus fishEven when kept in schools, discus fish can be very shy and stress in a tank that does not provide adequate hiding places. These fish can also be scared by moving shadows or excessive traffic near the tank, as well as loud noises and lights on and off. Although they are shy, discus fish are often active at night when the environment around the tank has calmed down.

One of the most unique behaviors exhibited by discus fish is their tendency to care for their young. Unlike many tropical freshwater fishes that eat their newborn eggs or fry, discus fish fry actually rely on their parents to feed during their first days.

The fry released in the mucus layer that grows on the skin of the mature discus fish. While adult discus fish are not likely to harm their young, the fry should be separated after about 10 days to avoid damaging the parents’ skin.

Although discus fish are generally not aggressive, they tend to form a pecking order that can be strictly enforced signs of aggression are more likely to be observed in pairs or smaller groups of discus fish than in larger groups where it can be difficult to identify a particular fish.

As your discus fish mature, they will naturally establish a pecking order and aggression may not be a problem. However, if a new discus fish is added to the tank, the dominant fish in the tank may feel threatened and may become aggressive towards the newcomer.

Discus fish show their aggression in the same way as other tropical freshwater fish species. They can be seen chasing around the tank or forcing an individual to a corner. The discus fish can also close the jaws, peck each other and, in extreme cases, slap their body against each other.

If the aggression of the discus fish is allowed to get out of control, the victim fish may become stressed or ill and could die if it does not take measures to remedy the situation. To prevent this situation from becoming fatal, discus fish must have many hiding places in the tank.

Live plants and rock caves can provide shy or harassed fish with a place to retreat, if necessary. If a particular discus fish is becoming too aggressive, it can be wise to remove it from the tank.

Discus Fish Nutrition

One of the most common mistakes made by novice aquarium hobbyists is the overfeeding of their discus fish.

Overfeeding can not only lead to unhealthy obesity in discus fish but can also generate an excessive accumulation of debris at the bottom of the tank. Not only is it important to feed the discus fish in the right amount, but it is also essential that they are given the right food.

Discus fish have strict nutritional needs that cannot be met with food in common scales. To keep discus fish healthy and prosperous, they should be given a varied diet of protein-rich foods, including live, frozen and lyophilized foods.

Nutritional Needs Of Discus Fish

Discus fish are carnivorous and, as such, require a high protein diet to thrive. Protein is composed of essential and non-essential amino acids, which are necessary for the nutritional well-being of discus fish. The diet of mature discus fish should be composed of between 35% and 45% protein but newborn fry and juvenile discus fish may require a diet that contains up to 50% protein.

Many novice discus fish breeders make the mistake of thinking that because discus fish are carnivorous, their entire diet must be made up of proteins. However, the excess protein in the diet of discus fish will break down into sugars during the process, the excess ammonia will be released in the tank water.

Fats, or lipids, are another essential component in the nutritional needs of discus fish. Although carbohydrates and proteins can be broken down into energy, fats provide discus fish almost twice as much energy as an equal amount.

Discus fish that have a fat-free diet may experience fin damage, stunted growth, decreased fertility and increased susceptibility to disease. The best source of fat for discus fish is crustacean oil, a substance that is often omitted from flake foods.

Like humans, discus fish also need vitamins in their daily diet. Vitamins are not used to produce energy, but they contribute to the growth and production of enzymes in the body.

Drying food destroys most of the vitamin content, so frozen and live foods are such an important part of the diet of discus fish. Algae, crustaceans, and vegetables are excellent sources of vitamin A and foods such as eggs, wheat germ, and green leafy vegetables also contain vitamins.

Minerals are as important as vitamins in the diet of discus fish. These inorganic compounds, especially calcium, are necessary for the growth of cartilage and bone. Crustacean, whole fish and bone meal supplements are some of the most common ways to add minerals to the diet of discus fish.

Types Of Food For Discus Fish

Live foods

One of the most popular types of live food for discus fish is blood worms. Actually the blood worms are not worms, but mosquito larvae. These larvae are rich in protein and can also be purchased in frozen or lyophilized form.

Tubifex worms are another popular dry and frozen food for discus fish, but if harvested from dirty sources, they can introduce harmful bacteria into the discus tank. White worms are a valuable source of fats for discus fish and should be offered several times a week.

Frozen meals

A variety of frozen fish foods are available, many of which are high in protein. Some popular types of frozen fish food include shrimp, fish, and plankton, in addition to blood worms, tubifex worms, and other insects.

Frozen foods retain a high percentage of their nutritional value and, as long as they remain frozen, they will remain uncontaminated. Depending on the type of food, some frozen foods are available in buckets that can simply be dropped into the tank; Food will be distributed as the bucket melts in the warm water of the aquarium.

These foods tend to be more expensive than freeze-dried foods, but the higher nutritional value makes it worth its price.

Freeze-dried Food

While some freeze-dried foods lose more than 50% of their nutritional value during the drying process, they remain an important part of the discus fish diet.

Some freeze-dried foods available in the market include tubifex worms, shrimp, plankton and crustaceans. These foods should generally be stored in a dry place, although some should be kept in the refrigerator.

Homemade Food

Even inexperienced aquarium hobbyists are able to create their own homemade food for discus fish. The most common ingredient in homemade foods for discus fish is beef heart. Beef heart is rich in protein but also contains approximately 18% saturated fat, which is difficult for fish to process.

Therefore, the beef heart should be used sparingly in the diet of discus fish. Chicken, lamb and turkey hearts can also be used in homemade fish foods, as well as cooked seafood such as mussels and cockles.

To make homemade fish food more convenient for distribution, grind it in a paste and mix it with gelatin as a binder, then place it in small balls so that it falls into the tank.

How To Feed Discus Fish

Discus fish should be fed with an amount approximately equal to 3% of their body weight. In a medium-sized discus fish that weighs about 75 grams, this would amount to 2.25 grams of food at each feeding.

discus fishWhile newborn fry and juvenile discus fish can feed more frequently, mature adults should feed twice a day. During each feeding, only provide the amount of food that discus fish can consume in three to five minutes. This will prevent the accumulation of fish food without eating at the bottom of the tank.

Administering live food can be complicated and can result in food dispersing throughout the aquarium. To avoid this, place live foods such as blood worms in cone-shaped feeders that float on the surface of the tank.

These feeders generally have holes or grooves large enough to allow discus fish to access worms in the cone. Flake and lyophilized foods can be sprayed on the surface of the tank in small quantities, although some discus fish can wait for the food to sink to eat them. Some freeze-dried foods, such as tubifex worms, come in buckets that can be attached to the side of the tank.

If discus fish have not consumed all their food within fifteen minutes, it is advisable to remove excess from the tank. While the fish can pick at some of the food that sinks to the bottom of the tank, most will simply accumulate and begin to break down into ammonia.

This is why it may be useful to have a few nicely selected bottom-feeding community fish in your tank, as discussed above since the food at the bottom will be taken care of.

By removing unconsumed fish food before this occurs, the water in the tank will be much cleaner. Together with regular water changes, these practices will create a clean and clear discus fish tank.

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