Beginner’s guide to Caring and Keeping for Dragon Fish(Arowana)

This chapter is about the care that should be exercised when rearing Dragon Fish in aquariums and the treatment for some of the common diseases to which the fish is prone.

Examples of aquariums showing how the Dragon Fish should be kept in open, uncluttered tanks with very basic filtering and aeration systems.
Examples of aquariums showing how the Dragon Fish should be kept in open, uncluttered
tanks with very basic filtering and aeration systems.

Fish Care and the Aquarium

The Dragon Fish is a large fish that swims about actively in the . Therefore, the basic rule to follow when reading it in an aquarium is to provide it with ample space in which to swim to prevent its growth being stunted.

Tank Location

Cover the tank and place it in a quiet area of the house, away from direct sunlight and constant human activity. Aeration and filtration are essential, but avoid tank furnishings which may damage the fish if it swims against them accidentally while trying to catch its food or when it is exciting.

Water Quality

As in all good fish practice, water should be maintained at a high level of quality, namely, with dissolved oxygen levels exceeding 5 ppm (mg/1) and a level of free ammonia not exceeding 0.1 ppm (mg/1). However, in your attempts to maintain good water quality, do not subject the fish to sudden changes of water as they need time to adapt to their new environment and would be stressed and fall sick easily if not allowed to acclimatize. The Dragon Fish is extremely sensitive to chlorinated water so if you use tap (potable) water, age the water for at least a day before use. Change the water every week, but only partially (not more than a third) to avoid upsetting the fish with the new water. Never alter the water pH or hardness suddenly because this can prove fatal to the fish. If any changes are to be made to pH and hardness, you should do these gradually to allow the fish to adapt to the changes. This also applies to any changes in water temperature.

Feeding Red Dragon Fish with shrimp in a home aquarium.
Feeding Red Dragon Fish with shrimp in a home aquarium.


Favorite foods of Dragon Fish are live insects (e.g. crickets and grasshoppers), small frogs and fishes such as Guppies and Mollies.To give the fish that gorgeous body colour, feed it with live shrimps. For convenience, the fish can be fed chopped fish meat. They will also take cockroaches and centipedes, but this is to be avoided as such creatures may be contaminated by insecticides. Young Dragon fish can be fed 2-3 times daily, while adults can be fed once daily, or even on alternate days.

1. Live food should constitute 75% of the feed given to Dragon Fish.

2. Keep all live food in separate tanks until you need to use it. Rinse small fish and shrimps to cleanse them of dirt before feeding to the Dragon Fish.

3. When feeding shrimps to Dragon Fish, it is best to remove the sharp shells to prevent the Dragon Fish from injuring its gut and stomach when ingesting. Avoid feeding whole shrimp to the fish, especially to young specimens.

Fish Transfer

The following equipment should be prepared when transferring a Dragon Fish to a new aquarium.

• Styrofoam box with lid in which to place the bagged fish.

• Plastic bags for bagging the fish.

• Oxygen cylinder or battery-operated aerators (air pumps).

• Newspaper, rubber-bands, adhesive tape, medication and scoop nets.

Before transfer

  • Starve the fish for two days before the transfer.
  • Check to see that the plastic bags are not leaking.
  • Clean and fill the new aquarium, ensuring that gray water is used and that the water pH and hardness are adjusted as closely as possible to what the fish is currently held in.

Procedure for transfer

  1.  Use a hand scoop net to net fish which are below 15cm (6in) TL, but use plastic bags to move fish exceeding 15cm. Use two bags together, with one bag placed inside the other.
  2.  In the water, face the mouth of the bag towards the fish s head, and gently nudge the fish into the bag.
  3.  Once the fish is in the bag, adjust the water level in the container to a depth that is about 1.5 times the thickness of the fish and twists the mouth of the bag.
  4.  If the fish can be transferred within 10-20 minutes into a new aquarium, there is no need to inject oxygen into the bag. For longer periods, it is necessary to insert the bag with oxygen and tie it securely. In this case, add a piece of newspaper as a lining between the two plastic bags, (a) to make the fish less excitable, as the paper keeps the inside bag dark and (b) to minimize water leakage if the inner bag is punctured.
  5.  At the new aquarium, float the entire bag (fish and all) in the water for 5-10 minutes to equalize the temperature of the bag water with that of the tank water.
  6. Open the mouth of the bag and gently allow the fish to swim out. Observe the fish in its new environment for 30 minutes.
  7. Leave the fish alone in the aquarium for a whole day. Do not switch on the lights during the day so that the fish is kept in the dark. However, in the evening it is best to leave on a dim light to minimize the risk of the fish leaping out of its new environment.
  8. It is not necessary to feed the fish until it is relatively more stable and acclimatized.

Diseases and their Treatment

The Dragon Fish is an adamant animal, having excellent resistance to most diseases as long as it is well maintained, given wholesome food, kept in water which is well aerated and clean, and not subjected to stress due to mismanagement arising from human negligence and ignorance of handling procedures.

The causes and symptoms of some of the more common diseases which may afflict the Dragon Fish are described below, together with their suggested treatment. Any treatments should be carried out either by a veterinary surgeon or someone with lots of experience with fish.

Tilted (Overturned) Gill Covers


  1.  Fouled water: this could develop as a result of rotting food particles and accumulated wastes in the aquarium. The high presence of organic matter in the water can reduce the level of dissolved oxygen (02) in the water, while free ammonia (NH3) and nitrite (N02) can be toxic to the fish.
  2.  Space constraint: the Dragon Fish needs sufficient space to swim around and, if this is lacking, can develop overturned gill covers.
  3.  Water temperature change: as the gills of the fish are sensitive to sudden water temperature change, any such sudden change, either becoming too hot or too cold, would cause the gill covers to become overturned.


At the onset of the disease, the fish shows the irregular movement of the gill covers and also breathes faster than normal. Later, the gill covers become concave, and the edges may curl outwards, causing the gills behind to be exposed.

As the disease becomes more severe and towards the final stage, the fish pushes its head always to the surface for air, and at the same time loses its appetite. By then, the gills within have become infected by bacteria, impairing breathing and leading to eventual death.


As soon as you notice that a Dragon Fish is not breathing properly, change the aquarium water immediately. Then every 2-3 days after that, change 20% of the water. Provide more aeration by installing another aerator and put in more air stones to increase the level of dissolved oxygen in the water. Also, the filter medium or media should be replaced with coral sand.

Fish with gill-cover deformity at an advanced stage.
Fish with gill-cover deformity at an advanced stage.


When the gill cover is slightly curled but not yet hardened, besides taking the above-mentioned measures, you should create a strong current in the water. This bill gives the fish a 50% chance of recovering without the need to subject it to an operation.

The gill cover deformity has been trimmed with surgical scissors.
The gill cover deformity has been trimmed with
surgical scissors.


However, when the gill cover is tilted and hardened, and gills are already exposed, the fish needs to have the hardened tissues of the inclined region trimmed off. For this, you need to have a pair of scissors, surgical spirit, gloves, plastic bag, rubber sheet and a piece of fine waterproof sandpaper. The scissors must be sterilized by flaming the cutting tips over the mind, while the other items must be new.

Operation procedure

  1.  Transfer the Dragon Fish to a smaller tank that has been filled with water to a level about twice the depth of the fish.
  2.  Replace the water in the first tank and make sure it is filtered and well aerated.
  3.  Administer anesthesia into the small tank (see here).
  4.  Once the fish has lost consciousness, promptly place it on a rubber sheet laid on a table.
  5.  Using the sterilized scissors, carefully trim the curled edges of the gill cover. It may be necessary to use fine sandpaper to scrape off any jagged edges.
  6.  After the operation, apply antiseptic lotion/cream to the trimmed edges.
  7.  The fish should be returned to the original tank to regain consciousness. Instead of letting the fish float in its unconscious state, hold it upright and direct an air stream from the aeration tube towards its gills to facilitate its recovery.
  8.  When it regains consciousness, switch off all the lights so that it can recuperate under dim conditions. There is no need to feed if the fish shows no interest in food.
  9.  Add 4 ppm (mg/1) of Acriflavine and 0.5% coarse salt to the water to minimize the risks of bacterial infection. Change 30% water daily for 3-5 days.

The trimmed portion of the gill cover must grow again fully before the operation can be considered successful.

Cloudy Eyes


  •  Eye injury as a result of poor handling.
  •  Contaminated water.
Specimen with drooping eyes and sunken cheeks
Specimen with drooping eyes and sunken cheeks


Initially, one eye may appear cloudy, then become moldy, as though a membrane is hanging over it. Eventually, both eyes may swell and become covered with a bluish foreign matter. If not treated at this stage, the fish may become blind or even die.


At the initial stage, change one-third of the aquarium water and add 0.5% coarse salt to the tank. Increase the water temperature to 30°C (86°F) or up to 33°C (91.4°F).

Specimen with pop-eye ailment - accumulation of fatty tissues behind the eye that cause the eye to pop-out.
Specimen with pop-eye ailment – accumulation of
fatty tissues behind the eye that cause the eye to


Observe for two days. If the fish s condition improves, change one-quarter of the water every third day and add more salt to maintain 0.5% salt content in the water until the fish has recovered completely. At the intermediate stage, use medication such as Acriflavine as a bath treatment to minimize bacterial infection and help recovery. Follow the instructions given for such medication. Acriflavine can be utilized at 4 ppm (mg/1).

At the stage where the eyes appear moldy, the fish will take about 2-3 months to recover if treated. If swelling subsides, medication can be reduced or even terminated. After recovery, the eyes may appear smaller, but that situation is typical.

Protruding Scales Disease

This often affects young Dragon Fish. Adult fish seldom develop this problem.


  •  Extreme temperature changes within the aquarium.
  •  Contaminated water due to poor water management.


At the initial stage, the scales tilt at every 5th to 8th level. Blood traces may be seen at the root of the scales. If not arrested at this time, the scales will gradually tilt, redness may appear, and the scales will not be able to protect the body against infection.At a later stage, the scales may all drop-off, causing the body to decay and the fish to die.


Add 0.5% coarse salt to the water. Also, increase the water temperature to around 30-34°C (86-93°F). Increase aeration to increase dissolved oxygen level in the water and change water by one-quarter every 3-4 days. Copper sulfate could also be added at 1-1.5 ppm (mg/1) to the water as a bath.

Rotting Gills Disease

This disease is highly contagious to other fish, and you should take precautions by thoroughly cleaning all the utensils after use.

Young adult with a damaged swim bladder.
Young adult with a damaged swim bladder.


The primary agent is a protozoan parasite which is not visible to the naked eye. It hides in the gills and derives its food by drawing on the blood of the host. The parasite multiplies speedily in temperatures of around 25°C (77°F). Polluted water, especially that which has not been changed for some time, carries such parasites.


The breathing rhythm of the fish is quickened, and it acquires a dull body colour.


Similar to that of White Spot Disease (see here).

Stomach Ailments

These occur when the fish is very young.


  • Mainly due to the fish consuming stale food.
  • Inflammation of the stomach due to injuries inflicted by the sharp pincers or shells of shrimp eaten by the fish


At the initial stage, the fish displays a swollen stomach and an enlarged anal region. At the advanced stage, an affected fish may lose its balance, swimming with its head dipped downwards.


At the moment, there are only limited means of treating this affliction. You could try raising the water temperature by 2-3°C.

‘Red Spot’ Disease

This is often regarded as a terminal illness and mostly affects young fish.


Due to bacterial infection as a result of poor tank management, such as an accumulation of uneaten food or fish feces in the reservoir leading to poor water quality.


Red spots appear on the lower back portion of the body.At the initial stage, patches of red spots appear and the body gradually swells, with scales becoming upturned. At the final stage, the fish may rot to death.


Bathe the fish in an antibiotic bath, such as oxy-tetracycline at 2 ppm (mg/1), for four hours.

Red Dragon Fish (Brownish-Red).
Red Dragon Fish (Brownish-Red).


Live food for Dragon Fish often acts as the carrier for pests.


The most common parasites of Dragon Fish are Fish Lice and Anchor Worm.

Fish Lice (Argulus): The parasite is approximately 3-5mm long (0.1-0.2in) and can be seen with the naked eye on the surface of the fish’s body. It has a flattened body shell, with a needle-like structure at the mouth to suck the body fluid of its host.

Anchor Worm (Lernaea): This parasite is found mainly around the fins or within the body of the fish, commonly in the gut. The whole parasite can be as long as1cm (just under 0.4in).


Besides finding the parasites on the fish body or within, you may notice that the afflicted fish are irritable, scraping and rubbing themselves against the aquarium sides, and losing their appetite for food.


The most efficient treatment to eradicate Anchor Worm and Fish Lice is to dip the fish in Dipterex* at not more than 0.5 ppm (mg/1) for a day. However, this should be done with extreme care, as an over-dose could kill the fish instantly. There should be vigorous aeration in the tank used for treatment. The first aquarium should be sterilized and thoroughly washed to rid it of the parasites.

Please note:

In some countries, Dipterex is either banned or restricted. Please check with your local authority.

‘White Spot’ Disease (Ich)

This disease is very common among fish and is highly contagious, hence the need to exercise caution and use proper utensils for each tank.


The parasite is the protozoan Ichthyophthirius multiplies that only attacks fish which are low in resistance.


At the initial stage, the disease mainly affects the fins. The afflicted fish tends to rub itself against the aquarium sides and bottom to try to get rid of the itch. The affected region looks as though it is covered with white powder. The fish loses its appetite, and the affected fin starts to rot. At the final stage, the parasite may attack the gills, with possibly fatal consequences to the fish.


  • 1% salt
  • Commercial medication for Ich.

Increase the water temperature in the aquarium by 2-3°C. Add either of the above to a bath. Place the fish in the tub for two hours. Meanwhile, clean the first aquarium thoroughly and disinfect it before refilling it with new, fresh water. Increase aeration in the first aquarium. During treatment, the fish should be given nutritious food to allow it to build up its resistance.


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