Are Discus Fish Aggressive? How To Keep Them Calm

Are my Discus Fish Kissing or Fighting

Are Discus Fish Aggressive? How To Keep Them Calm7 mins read

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Are discus fish aggressive

The Discus is one of the most elegant aquarium fish, but are discus fish aggressive? After all, some colorful fish like bettas can be very aggressive.

Don’t worry! Discus fish are generally not aggressive. Instead, they are peaceful and social. Though in a few rare scenarios, and of course being part of the cichlid family, Discus Fish Aggression can break out.

It is crucial to fully comprehend the intricate care needs, if you want to understand discus fish and aggression. This article will cover the question of ‘discus fish, are they aggressive?’ as well as to prevent any chances of aggressive behavior.

Discus Fish Are They Aggressive And Why?

Discus fish are they aggressive and why?
A hungry Discus will become aggressive and compete for food, and the stronger more dominant fish may eat all the food and deprive the weaker ones.

You may wonder about discus fish, are they aggressive despite their beauty? Fortunately these guys are not like the betta.  Knowing their care requirements means you can understand whether they are aggressive in more detail.

Over many platforms, discus fish are Peaceful and social fish that are rarely prone to aggression in contrast to other cichlid species. Though there is somewhat more about aggression in Discus fishes.

Are Discus Fish Aggressive?

So, are discus fish aggressive? To answer the question, according to many studies, Discus fishes are one of the most peaceful fish species from the cichlid family. However, keep in mind they are still cichlids that do carry the general temperament of becoming aggressive at times. Due to this, discus fish and aggression makes sense when you think about hierarchy.

Aggression in freshwater fish can happen when fish chase each other. Or, they may slap their bodies against each other, and pick at each other. But regards to hierarchy, are discus fish aggressive?

Sadly, in most cases healthy fish tend to pick on weaker or ill fish to remove the “weaker links”. Furthermore, and ill fish will tend to be more shy and sluggish.

The best way to prevent aggression in Discus fish is to always keep them in larger groups.

If there still seems to be aggression in Discus fishes, you can solve this. This aggression may be towards each other, or other fish species in the Aquarium. Generally, there are a few reasons that can indicate why:

  • Pecking Order

Discus fish have a pecking order (hierarchy), in which you will have dominant and more submissive individual fish in the group. Adding a group of young discus fishes may take some time to establish a pecking order.

However, with mature discus fishes there may already be a pecking order. Adding a mature Discus to an aquarium with younger ones, or adding a new discus to a group may interfere with the pecking order and cause aggression.

  • Dominant Behaviour

In some cases there may be a more dominant individual Discus. This fish will show aggression towards the other more timid Discus fishes to establish dominance.

  • Spawning and Breeding

As a rule, the answer to ‘are discus fish aggressive?’ is a no. But what about when you are breeding them? During Spawning males become aggressive towards other males to secure their partners. Females may become aggressive in trying to protect their eggs. As a rule, discus fish and aggression is most important to consider when breeding. And, in the case of a tank with fewer females than males, the males may fight over suitable females.

  • Territory Conflict

Naturally Discus fishes will be territorial when breeding, protecting their space. Generally, discus fish and aggression takes place during breeding. They are usually only aggressive towards fish of their species.

  • Lack of Space

When too many Discus and other fish species live in a tank, it becomes overcrowded. Furthermore, territorial issues may become more prominent, causing aggressive behavior.

  • Food Fights

A hungry Discus will become aggressive and compete for food. Sadly the stronger more dominant fish may eat all the food and deprive the weaker ones.

  • Poor Aquarium Conditions

Poor water conditions that do not fit the correct parameters can quickly cause stress in discus fishes. Although observing discus fish and aggression is generally uncommon, these conditions may lead to some form of aggression.

  • Incorrect Ratio

Discus fishes are known to thrive in groups, the smaller the groups the more aggression is likely. It is always advised to keep groups of between 4 and 6 that are within the same age group or relative size.

Dealing With Discus Fish Aggression

  • Feeding

When feeding, spread the food around all over the tank. This is so that each discus and other fish species can get enough to eat.

  • Changes to Aquarium

If discus fish aggression happens for no apparent reason, you can try to change the tank around. This will break down territories, and keep them from fighting.

  • Add More Fish

Larger groups of Discus fishes do not tend to display aggression. Ensure that you purchase them in a group, and they are around the same size.

  • Newcomers

Your Discus fishes may not take kindly to single new Discus fishes added to the tank. If you’re wondering about aggression in discus fish, are they aggressive to newcomers, this is one of the most likely circumstances. This is especially if they are younger. Rather add all your discus fish at once.

  • Tank Size

Ensure that the aquarium is the correct size for your Discus group and other fish species. This is as a lack of space can cause much stress.

  • Breeding

You may try to separate breeding pairs into a separate breeding tank. Are you wondering when breeding, are discus fish aggressive? This is also another main time for aggression. So, a separate tank is always good practice to avoid aggressive behavior towards other fish during this time.

Thus, when kept in larger groups, with ample space and proper water conditions, your Discus fish should get along quite peacefully. If they are well-fed and have space for breeding territory, fighting and aggressive behavior should reduce.

Discus Fish And Aggression Towards Other Fish

Discus fish and aggression towards other fish
The Discus is noted for its tranquility, and peaceful nature, especially towards other fish species. Image from Flickr

The Discus is noted for its tranquility, and peaceful nature, especially towards other fish species. There is generally a greater chance of larger more aggressive fish species bullying a discus.

So, are discus fish aggressive? According to studies the only times there was aggression by Discus fishes towards other fish species were during breeding. This is to protect their territory and may be a sign they feel threatened.

Good advice is to add your Discus group to an aquarium that already has other companion species or to add all species at once. This is because Discus fishes tend to form a pecking order and may show slight aggression towards newcomers.

What Are Other Suitable Fish Species As Companions?

On the topic of Discus Fish and Aggression towards other fish species, there are a few peaceful species that will easily get along with Discus fishes, without any aggressive behavior:

  • Corydoras Sterbai – They are peaceful bottom feeders that clean the bottom of the tank.
  • German Ram – A Dwarf Cichlid species that will add a splash of color to your aquarium and get along with the Discus fish.
  • Marbled Hatchetfish – Calm and peaceful bottom feeders that enjoy some floating plants to hide in.
  • Rummy Nose Tetras – They are small and eye-catching with a similar diet to that of the Discus.
  • Harlequin Rasbora – Both attractive and very calm fish species.
  • Siamese Algae Eaters – Bottom-feeding algae eaters that will not compete with a Discus for food.
  • Rainbow Fish – When kept in larger groups, they are striking and calm.

Now you have learned more about Discuss Fish and Aggression, here is some more info about their general care. This should help answer ‘are discuss fish aggressive?’ and ‘in what circumstances do you see Discus Fish Aggression.’ Remember, a fish that lives in ideal conditions is less likely to be aggressive.

Discus Species Information

The Symphysodon, or as it is informally known the Discus is a class of cichlid species. Cichlids as a family of fish species, especially African origin Cichlids are notorious for being very aggressive. However, the Discus is one of the more peaceful and passive Cichlids species. It originates from the Amazon River basins in South America.

Discus fish have a very distinctive shape, with bright colors and patterns. They have remarkable behavior, and Discuss Fish Aggression is rare, making them popular in the aquarium trade. What’s more, they are quite striking and popular among international breeders and collectors. Discus are especially popular as show breeds for their elegance and intriguing colors. Some Discus variations and colors are rare and expensive.

Though found in both blackwater and white water bodies but prefer lentic habitats (still water). This is including flooded plains and forests with mostly white water that has suspended materials, rather than rivers and streams.

It is important to understand discus fish and aggression, though. According to many breeders, the Discus is a fish species that is better for advanced aquarists.

These are those that have the knowledge and resources for their strict care requirements in terms of water quality and aquarium set-up. Furthermore, the Discus is a larger fish as an adult growing to between 8 and 10 Inches (20-25 cm), that needs to live in groups of its species. Furthermore, the answer to ‘discuss fish, are they aggressive?’ can depend on how good their water quality is.

Similarly, they have a long lifespan of between 10 and 15 years with proper care.

A Few Interesting Facts About The Discuss

  • The Discus has the name of the “King of the Aquarium Fish”.
  • It forms part of the Cichlid family, however is more peaceful than most species from this family.
  • The Discus is a unique Cichlid from America that prefers to be in groups of its species.
  • When a Discus experiences extreme emotions, especially fear, the color of their skin will become much brighter.
  • They are ideally mostly carnivores, though quite peaceful and not cannibalistic towards their young.
  • They are relatively slow swimmers, hence why they prefer staying in groups.
  • The Discus requires extremely clean and warm water and can be sensitive to changes in water parameters.
  • Discus fishes are naturally superb parents, couples will separate from the group and males and females take care of their young.
  • The female Discus secretes a “Discus Milk” from her skin to feed her young during the first 4 weeks.
  • Male Discus fishes are contrarily larger than females.

What Does A Discus Look Like

What does a discus look like
The Discus has a laterally compressed body with a rounder shape than most Cichlid species, hence why it is known as a “discus” fish.

The Discus has a laterally compressed body with a rounder shape than most Cichlid species. This is hence why it is known as a “discus” fish. It has more extended fins, and patterns on the body that are typically shades of red, brown, green, or blue. Due to selective breeding, more colorful variants are available that do not naturally occur in the wild. As mentioned the Discus can change color. This is especially when experiencing certain emotions, becoming much brighter and bold in color.

Some of the most common colors bred in the aquarium trade are:

  • The Red Turquoise Discus
  • White Dragon Discus
  • Golden Calico Discus
  • Heckel Cross Discus
  • Blue Scorpion Discus
  • Cobalt Blue Discus
  • White Diamond Discus
  • Albino Millenium Golds
  • Mercury Discus
  • The Red and Orange Pigeon Blood Discus

Discus Behaviour And General Temperament

In comparison to other Cichlid species, Discus fishes are relatively calm, peaceful, and slow-moving fish. However, the answer to ‘are discus fish aggressive?’ is it depends. In fact, they can become slightly aggressive especially when spawning, and may pick on weaker fish of their species.

Generally known to be social and having a preference to congregate in groups, Discus fishes similarly are excellent parents, both taking care of their young until they are independent enough to fend for themselves.

Discus fishes are prone to bullying from other more competitive fish species. It can stress them out easily when you keep them with more aggressive or territorial fish species.

Caring For A Discus

sign of discus fish is going to die
A large tank of between 55 – and 75 gallons will be required for a group of four or more Discus fishes.

It is vital to cater to the very specific care needs and water conditions of a Discus for it to flourish, as they can be relatively sensitive. By managing water parameters and keeping their aquarium in pristine conditions, it is easy to successfully keep Discus fishes. Keep in mind that should live in groups of four or more to feel safe and stay calm.

  • Setting Up an Aquarium

A large tank of between 55 – and 75 gallons is still necessary for a group of four or more Discus fishes. Similar to their natural environment the Discus prefers water with a low current that is clean and clear, thus taking care when purchasing a filter. Most hang-on back filters are ideal. They prefer more tropical climates and higher temperatures of around 26 to 30°C between (80° and 86° F), except the Heckel Discus species that prefer slightly higher temperatures of around 32°C (90° F).

A water pH of between 6.0 and 7.5 is suitable, and they prefer moderately soft water conditions, ideally, water that has undergone Reverse Osmosis (OR) treatment, with additional salts and minerals, is the recommendation of most knowledgeable Discus keepers. Generally, Discus fishes prefer a more natural environment with plenty of open space for swimming, additional rocks, driftwood, and a few live plants.

  • Feeding

The Discus is an omnivore, because it will feed on algae and certain plant materials, though they are mostly carnivorous. A diet rich in protein-based foods such as specific Discus flakes, Shrimp, Bloodworms, Insects, and larvae is best, along with algae rounds and corn flakes.

  • Regular Tank Maintenance

Additionally tank cleaning and maintenance are vital when keeping Discus fish, they need clean and clear water with optimal parameters. It is advised to regularly replace tank water by siphoning at least 25% of the water from the bottom and replacing it with clean OR, and conditioned water that is the proper climate. Maintenance is ideal at least once a week.

  • Breeding

Though adult male Discus fishes are larger than females. Apart from this, though, there are almost no discernible differences in them besides their genital papilla. The Males have pointed longer genital papillae, while the females are more rounded. Keeping a group of Discus fish will ideally enhance the chances of having males and females. These will eventually pair off by themselves during the spawning season.

Mated pairs will become more territorial and claim a space to lay their eggs. This is usually low on the ground. You can use PVC Pipes or terracotta pots to create a safe environment for laying eggs. Discus fish are nurturing parents that will take care of their young. However, you can feed them baby brine shrimp as soon as the fry starts swimming independently.

Common Health Issues

In peak conditions, Discus fishes will thrive and remain essentially disease-free. However, there are a few common health conditions that may affect them:

  • Internal Parasites

One of the most common internal parasites that are prone to affect a Discus is Hexamita. This is a small parasite infecting the small intestines. Symptoms include white excrement, fish losing weight, or a hole in their head. The parasite responds to Metronidazole, according to specifications given by a vet. Discus fish rarely contract other worms or parasites, such as tapeworms. Remember, parasites can make any fish aggressive sometimes due to causing pain.

  • Cloudy Eyes

A very common ailment that is prone in Discus fish is called cloudy eyes. Usually, physical damage to the eye or a sudden crash in the pH balance of your tank are the culprits. Luckily you can treat it with salt or medication containing Aloe Vera.

  • Fin Rot

Fin Rot is a common condition in most freshwater fish species. It comes as a result of a bacterial infection, because of damage or injury to the fins of the fish. By placing the fish in a quarantine tank with clean water, and using a broad-spectrum antibiotic the condition should clear up easily.

  • Bloating

Just as humans are sometimes prone to bloating because of excess gas in the stomach or constipation, Discus fishes can similarly suffer the same symptoms.

The easiest treatment is to add a tablespoon of Epsom salt per 40 liters in your tank. You can also raise the temperature slightly. The treatment will increase the metabolism of your fish, and you may notice some excess excrement in the tank. In which case after a few days a proper water cycle must happen. Adding a mild metronidazole treatment to the water will help too. This is in case the Hexamita parasite decides to develop in the excrement of your fish.

In The End

A tank with a group of Discus fishes of around the same size, and a few other peaceful community fish is ideal. This is a much more balanced and calmer environment for your Discus fishes. The answer to ‘are discus fish aggressive?’ is generally no. However, these fish are sensitive. Thus they may receive aggression or cause it during breeding.

There is not much to be troubled about concerning discus fish and aggression. Generally they are famous for being peaceful and sensitive. Thus, it is only in a few rare cases where some aggression is noted.

Frequently Asked Questions

Are my Discus Fish Kissing or Fighting?
“Kissing” is pecking behavior usually seen between two males establishing dominance. In the case of a pair, there will be more gills flaring, and the male will peck at her gills and not her mouth.
What Does Tail Slapping Mean?
Tail slapping is a sign of aggression rather than wanting to mate. Usually, a male and female pair will perform a slight bow when they are flirting with each other, rather than tail slapping.
Are Angelfish Aggressive Towards Discus Fish?
Angelfish are generally peaceful, however, they can become especially aggressive when breeding or during feeding time and may tend to pick on Discus fish.
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Tal Halperin

Tal is an avid fish keeper and has been raising ornamental fish for decades. As a little boy, he drove his father crazy to buy him an aquarium with all the necessary equipment. Now, after a career in the field, he has set up Your Aquarium Place to offer the most comprehensive guide to ornamental fish keeping available and share his passion for the different species he has looked after.