Scientific name: Flowerhorn
Common name: N/A
Usual size in fish tanks: 24 - 28 cm (9.45 - 11.02 inch)
Recommended pH range for the species: 7 - 7.5
Recommended water hardness (dGH): 6 - 25°N (107.14 - 446.43ppm)
0°C 32°F30°C 86°F
Recommended temperature: 25 - 30 °C (77 - 86°F)
The way how these fish reproduce: Spawning
Where the species comes from: Cultivated form / Hybrid
Temperament to its own species: aggressive/territorial
Temperament toward other fish species: aggressive/territorial
Usual place in the tank: Middle levels
The Flowerhorn species does not exist in the wild, since it is a hybrid between Amphilophus citrinellus and Cichlasoma trimaculatum. Because of this reason, it has no scientific name (we list its scientific name as Flowerhorn due to our internal records).
This fish is also known as Flower Horn, Lump Head Cichlid, Malaysia Rajah Cichlasoma, Hualorhan, or Luohan. Flowerhorns were originally bred in the Central America and due to their size, they require large tanks; at least 300 litres (79.25 US gallon, 65.99 Imperial gallon) per 1 adult fish. Males are more aggressive than females. Give them enough empty space and don't keep 2 adult males in one tank, since the stronger one will likely kill the second one. If you consider keeping Flowerhorn with other fish, make sure they're aggressive and large enough.
Aquarium set up
The flowerhorn has very little requirements to keep them happy in the aquarium, indeed some keepers house them in aquariums with no substrate or décor but we feel that this is not always beneficial to the fish. If adding substrate user the larger gravel, the Flowerhorn spends a lot of time rooting amongst the gravel, using smaller grade could mean that some of this will be eventually digested. As they do disturb the substrate it is not ideal to add plants but they will appreciate a couple of hiding places, these can be provided by placing some upturned terracota plant pots in the tank.
They are high waste producers so always use a good quality filtration system and perform regular water changes.
They are an hardy fish and can accept a wide range of water parameters but the water quality should still be kept as high as possible to make sure that they live long and happy lives.
Feeding the Flowerhorn
Feed them snails, small fish, earthworms, pellets, tablets. They do have a voracious appetite so do not overfeed the fish, two meals a day is plenty and any uneaten food should be removed from the aquarium if it is still present 15 minutes after feeding.
Breeding the Flowerhorn
Breeding isn't very difficult. You need to increase the temperature and you will soon see the pair hovering around the heater of the tank, once this happens the female should be ready to lay her eggs. During this time they will become aggressive even to their owners so caution should be shown particularly at feeding times. The eggs will be laid on a chosen spawning site such as flat rocks or even pits dug in the gravel. The eggs should hatch after 3-4 days and a few days later the fry will become free swimming, once this happens they can be fed on small meals of brine shrimp. You may notice some aggression between the male and female, if this occurs then a separator may be required to keep both fish safe.
Questions and answersVisitors of Aqua-Fish.Net keep asking questions and we keep answering them; That's how the below-listed questions were collected and answered later. On March 19th 2011 they were merged with this page after being published at aqua-fish.net/answers for some time. If you want to ask, then use a form at the bottom of this page, please (ensure that your question hasn't been answered on this page already).
Why can’t my flowerhorn tell which way is up?
Answer: It could be a common case of swim bladder disorder. The swim bladder is the organ that allows a fish to know which way is up or down. Swim bladder disorder is the condition that messes up the equilibrium of the fish causing it to become disoriented.
What types of fish can I keep with flowerhorns?
Answer: Because of the aggressiveness of the flowerhorn fish, it is not recommended to keep anything other than another flowerhorn with them, however if your tank is large enough and has enough hiding spaces you may be able to keep a pleco or other large cichlids with your flowerhorn.
What size fish tank is better for my flowerhorn?
Answer: Flowerhorn cichlids can grow to be over a foot long and can live for as long as 12 years. When small, the flowerhorn can be kept in a 55 gallon (250.04 litre, 66.05 US gallon) aquarium with plenty of caves and territories. As it gets older, the flowerhorn will require a much larger space of at least 125 (568.26 litre, 150.12 US gallon) gallon tank.
My flowerhorn has laid eggs, what do I do now?
Answer: Flowerhorn make very good parents protecting the fry, let them get on with the job of incubating the eggs; it may take a few batches before you get any successful hatchings. Keep an eye on the male to make sure he is not aggressive to the female, if so then separate the fish with a tank divider.
When do flower horns start growing a hump?
Answer: The hump on the forehead develops as the fish ages; it is usually more dominant on the alpha male. There is no fixed age; some males develop the hump quicker than others.
How do you sex flower horn fish?
Answer: Sexing these fish is generally easy, as adults the female will have a smaller hump.
When does a flower horn grow full size?
Answer: Flower horns live for 8-10 years and are normally fully grown at 18 months but it may take longer for the nuchal hump to appear on their forehead.
Special thanks goes to Bien Gutierrez, Kevin and Remy Tran who have allowed us to use his picture.