Key points of flowerhorn cichlid keeping techniques in aquariums

Flowerhorn (F1owerhorn) is a general term for the multi-hybrid descendants of several species in the family Cichlidae (Cichlaidae), mainly from parents of the genus Cichlasoma. Because of their strange appearance and brilliant colors, flowerhorns were sought after by a large number of ornamental fish enthusiasts as soon as they appeared, becoming popular throughout Asia within three or four years and becoming a new favorite among ornamental fish. It has been only 10 years since the birth of the flowerhorn, and only 5 years since it entered mainland China. Its keeping techniques are introduced below.

I. Biological characteristics

Due to differences in the parents, multiple strains of flowerhorns have been formed, mainly including the flowerhorn strain first created in Malaysia, the golden flower strain, the flower horn strain, and the pearl strain; the flower leopard series, red leopard series, and colored diamond series bred in Taiwan, China; and Thailand's red star series, golden tai sui series, and so on.

Even so, flowerhorn fish can be classified as one group because they naturally share common features. In terms of morphology, such as skeleton, fin formula, lateral line, and body shape, flowerhorns retain the common characteristics of the family Cichlidae: they are medium-sized fish, with adults 20-40 cm in body length (there are differences among strains; the flowerhorn strain has the largest individuals, with a maximum body weight of up to 5 kg), a stout, laterally compressed body that appears oval from the side, and extended soft rays at the rear of the dorsal and anal fins, making their outline appear rectangular. The head is humped, the snout is short, the mouth cleft is medium-large, the lips and teeth are fine, dense, and sharp, the eyes are medium-large, and the sclera is red. The colors are bright and rich (strains not originating from Malaysia are often of a single hue), the chest is mostly bright red, and in addition to skin pigments, the surface layer of the scales often has golden flaky or dotted reflective material. In addition, there are often black spots along the lateral line.

In terms of living habits, flowerhorns are almost the same as their ancestors: carnivorous, able to take pellet feed, fierce and combative in temperament, with especially severe cannibalism among the same species, and a habit of occupying territory. The female-to-male ratio is close to 1:1, and males are clearly larger than females and also grow faster than females. Females mature at about 6 months of age, while males mature from 8 months to 2 years. Males and females pair up on their own and lay adhesive eggs on stones or stone slabs, and they have the habit of protecting the eggs and fry (this is why the family Cichlidae is called the cichlid family in the ornamental fish world). They prefer weakly acidic to neutral water quality and do not have high requirements for dissolved oxygen or hardness conditions.

The final rearing water body for flowerhorns is the aquarium, and every stage of the flowerhorn life history can be completed in an aquarium, so the techniques for keeping flowerhorns in aquariums are mainly introduced here.

II. Construction of the water environment

The survival water temperature for flowerhorns is 22-35°C, and the optimum water temperature is 26-30°C. Water quality requirements: dissolved oxygen >=5 mg/L, pH between 6.0 and 7.0. There are no strict requirements for other physical and chemical conditions, and ordinary aquariums, cement ponds, and ponds can all satisfy them.

The size of the aquarium for keeping flowerhorns should match the size of the fish. Generally, the length of the aquarium should be equivalent to 3-5 times the total length of the fish. If more other fish are kept together, the aquarium needs to be even larger. The most commonly used in homes is a standard aquarium of 80-120 cm.

For productive aquaculture, there is no need to place decorative items in the aquarium. For purification equipment, an overhead filter or a multi-tank shared circulating water purification system can be used. Do not use aerated biochemical sponge filters, to avoid them being bitten to pieces by the fish, and there is also no need to install additional aeration equipment.

For home keeping, generally an overhead filtration system, or an external canister filter, or a hang-on filter, or an undergravel filtration system is installed. For beauty and decoration, sand can be spread on the bottom of the tank and covered with a layer of pebbles or colorful stones, 1-2 pieces of driftwood can be arranged, and a small amount of water plants with relatively strong impact resistance can be planted, such as Java fern, water plantain, and ferns.

III. Feeding management

1. Stocking. Flowerhorns over 10 cm cannot be kept in the same tank with the same species, but they can be mixed with certain other fish that are larger than they are. These fish include: arowana, redtail catfish, parrot cichlid, pig fish, pleco, firemouth cichlid (Cichlasoma meeki), and severum (Cichlasoma severum), etc. When mixing, the total number of fish in the aquarium must be an odd number, such as 3, 5, or 9, which can reduce fighting.

For productive aquaculture, in order to effectively use space and at the same time make the fish more colorful, a glass plate is often used to divide the aquarium from the middle, with one flowerhorn placed on each side. They can see and smell each other, stimulating their desire to fight and prompting them to secrete hormones, which can enhance coloration and promote enlargement of the forehead.

2. Feeding. The feed for flowerhorns usually includes small fish, small shrimp, fish pieces, meat pieces, fresh mixed meat balls, pellet feed, etc. Feed 1-2 meals per day, with each meal of fresh feed equivalent to about 5% of the fish's body weight, which can ensure they are basically full without leaving residual feed. It is best to often feed some small shrimp, or add a certain amount of shrimp meat, astaxanthin, carotene, and other vitamins to the mixed feed, which is beneficial for health and growth and development, and can also increase the bright red color of the body surface.

In aquariums where multiple kinds of fish are kept together with flowerhorns, the fish generally paired with them are all carnivorous, so only one kind of food can be fed per meal. It is best to feed less minced fish food, to avoid residue produced during food competition polluting the water body;

3. Water quality management. Generally, tap water after aeration and dechlorination is used. If the pH is higher than 7.0, it can be adjusted with an acidifier or a mixture of phosphoric acid and sodium dihydrogen phosphate (in fact, flowerhorns can also adapt to a pH as high as 7.5, but it is not as good as weakly acidic water). As for hardness, ordinary tap water generally meets the requirements, and no special adjustment is needed.

For an aquarium with a single flowerhorn (or two separated), change the water once a week, about 1/3 each time. For mixed keeping of multiple fish, change the water once every 3-7 days depending on water clarity, about 1/3 each time.

IV. Disease prevention and control

Flowerhorns have relatively strong disease resistance and rarely become ill, and no phenomenon of large-scale infection causing disaster has been found, but disease prevention and control still cannot be ignored. A relatively common disease prevention measure is to regularly add table salt. Once every 2 weeks, adjust the salinity in the aquarium to 0.5%, keep it for 24 hours, and then gradually return it to normal.

In aquariums with mixed keeping, because of occasional fighting and biting, external injuries occur from time to time. If the salinity is immediately raised to sterilize, wound infection and worsening can generally be avoided. Once a wound becomes infected, it can be soaked with antibiotics (penicillin and oxytetracycline hydrochloride are more commonly used), and if enteritis occurs, norfloxacin can be used for intestinal perfusion.

V. Reproduction

Flowerhorns have the habit of choosing mates on their own, but reproduction in aquariums is often by artificial pairing.

1. Male and female identification. You can directly look at the genital papilla. Females have a larger genital papilla, U-shaped, while males have a smaller genital papilla, V-shaped. For flowerhorns originating from Malaysia, males and females can also be judged by the black patch on the dorsal fin: female individuals have a black patch in the middle of the dorsal fin, while males do not.

2. After placing a mature male individual into the aquarium, place the female fish in the next day, separate them with a glass plate or iron mesh, remove the separator after 3-7 days, and place in a tile or an inverted porcelain plate as an egg attachment plate. At this time, observe the situation in the aquarium carefully; the difference between courtship behavior and violent fighting is obvious. Once violent fighting occurs, the female fish should be removed immediately and paired again. If the pairing is ideal, spawning may occur within 24 hours, with 500-1000 eggs per spawning. Take out the spawning plate with the eggs attached and place it in another aquarium for hatching. The hatching time of fertilized eggs is about 48 hours.

3. After hatching from the membrane, the fry begin to feed 48 hours later. Flowerhorn fry are relatively large, and at first feeding they can eat small cladocerans and rotifers. On the 3rd day after first feeding, they can eat ordinary cladocerans.