The Flowerhorn - A Controversial Aquarium Fish


Hybridisation between fishes of different species is a well documented phenomenon. In the case of quite a few fishes, naturally occurring hybrids are known. For example, certain Centropyge Dwarf Angelfishes from coral reef habitats will hybridise naturally - eibli x flavissimus, flavissimus x vroliki, eibli x vroliki, loriculus x potteri and multifasciatus x venustus are all documented naturally occurring hybrids, with several other possible crosses awaiting verification. In the world of more accessible freshwater aquarium fishes, Poeciliid livebearers have been hybridised in the aquarium to increase the colour varieties available in fishes such as Mollies and Swordtails (the familiar Green Swordtail, Xiphophorus helleri, being readily hybridisable with the Platy, Xiphophorus maculatus, for this purpose) and in the world of livebearers, hybrid varieties of Mollies and Swordtails outnumber their natural ancestors in the aquarium by a huge ratio. However, the ease with which these fishes will cross in the aquarium suggests that they will hybridise in the wild too, given the opportunity, and this has led to the fishes being useful in the genetics laboratory, where scientists have been studying them for decades. This has led to a general acceptance of livebearer hybrids in the hobby, though of course for show purposes, control of pedigree important in maintaining a 'pure' strain in the case of several of the fancy varieties that have come into being since the 1960s.

The discovery that Cichlids were capable of hybridising (among the earliest documented examples were of Cichlasoma facetum x C. spilurum hybrids illustrated in the October 1977 issue of Tropical Fish Hobbyist magazine, in the 'Mail Call' letters section accompanying a letter on Cichlid hybridisation on pages 69 & 70) was, at first, considered little more than a curiosity, and in those early days, the experimental crosses were infertile for reasons that at the time were unknown. Later revision of the entire Family Cichlidae by Dr Humphrey Greenwood and Sven Kullander enlightened us to the fact that many of the early crosses were between fishes that occupied different Genera as well as species - the Genus Cichlasoma as originally constituted (in the 1970s this was a LARGE Genus containing some 200 species or so!) was broken up, and most of its constituent fishes reassigned to other Genera, such as Heros, Amphilophys, Cryptoheros, Archocentrus, Vieja and Nandopsis. Once the taxonomic revision was complete, hybridisation experiments could then be conducted upon a more rigorous scientific basis. Other Cichlids that were discovered to be capable of hybridising, and which would sometimes do so spontaneously in the aquarium under the right conditions, were Aequidens rivulatus, the Green Terror, and Aequidens pulcher, the Blue Acara. Green Terror/Blue Acara hybrids sometimes occur in the aquarium with such ease that it is worth speculating whether or not natural hybrids of these two fishes can occur - and, as a corollary, whether or not pulcher and rivulatus are two species that have only very recently diverged from a common ancestor. We shall, of course, have to await the publication of the genomes of these fishes to establish this on a rigorous scientific basis, but given the modern understanding of 'species' as being a dynamic entity, speculation in advance of the appearance of the actual data is perfectly possible and a legitimate motivator to those who will in time provide the data!

So, the groundwork was laid for the creation of Cichlid hybrids. In the fullness of time, this led to the creation of the Flowerhorn - a hybrid Cichlid that in some cultures and among some aquarists, is highly prized, but arouses an entirely different reaction in others ...


While some may consider it rather odd that, for example, hybrid livebearers be accepted in the hobby with barely a murmur, while hybrid Cichlids arouse heated argument, there is a basis for this. Cichlids are highly evolved fishes, with numerous well documented and demonstrated examples of intelligent behaviour, and moreover in the case of the Central and South American species that have been the focus of Flowerhorn hybridisation, possess behavioural attributes that endear them to their keepers because they are, somehow, "like us" - they form monogamous pair bonds, engage in considerable labour during reproduction to care for their eggs and fry, and in doing so evoke an empathy between themselves and the human aquarist that is hardly ever seen outside the world of mammalian pets. For an evocative example of this, try the following extract from Cichlid Comparisons, an article by Donald. J. Scheer, from the April 1977 issue of TFH (pages 4-15 and 86-91):

"When a pair of managuense, for example, spawns and is caring for eggs and fry, they must evoke human empathy. There is my tough-looking male with a twisted mouth, veteran of dozens of Cichlid fights, sitting sheepishly inside a flowerpot in the wee hours of the morning domestically fanning his mate's eggs. As a father, I can relate to that big fish, for I too have spent nights awake comforting and caring for my baby. That fish and I are united in some strange kind of pantheistic way, two living beings bonded together for a single procreative purpose."

Donald Scheer's words will doubtless resonate very loudly with Cichlid fans old enough to have continued their hobby with the demands of human parenting - those fishes posses that ineffable aura of 'being like us' in key ways that strike a chord with something deep in the human psyche. As a consequence, they evoke a much more vigorous reaction when subject to anything that may be considered 'abuse', in much the same way that kicking a dog is regarded as an act of low, vulgar brutality. For quite a few Cichlid keepers, big Jags, Oscars, Dempseys and the like are creatures we don't so much keep, as commune with - given that they are brim full of personality, and reflect aspects of our own human natures in their own activities, the feeling arises in many people that these are not creatures that should be 'messed with'. The overriding thought that occurs in the minds of those who bristle at hybridising Cichlids is that this is somehow 'not natural' - these fishes are not recorded in the main as hybridising in the wild (for example, Ron Coleman in The Cichlid Room cites that while Convict Cichlids, Archocentrus nigrofasciatus, share their natural habitat with another fish called Archocentrus septemfasciatus, they do not appear to hybridise in the wild) even though they may be persuaded to do so in the aquarium (Convicts and septemfasciatus will hybridise in an aquarium in the absence of mates of their own species). Since naturally occurring hybrids of these Cichlids are not documented as occurring, there is the suspicion that hybrid Cichlids are somehow the result of 'manipulation' by Man, and since we have very good reason to be alarmed when some of our fellow humans are 'manipulated' with respect to sexuality, the same thought crosses over to what is happening with the Cichlids. Since any 'manipulation' of humans and human sexuality inevitably involves coercion against the will of those affected, and in these relatively enlightened times this is considered singularly offensive to our dignity, there is a sense that somehow, Cichlids that are 'manipulated' into hybridising are 'suffering' in some way. A view which can be held with equal vigour by those who oppose such activity either from a theological or a secular standpoint.

Additionally, there is the matter of the fitness of the offspring. Those original facetum x spilurum hybrids documented in the 1970s were described as being sterile, and unable to reproduce themselves. In a sense, they were 'less fit' than their parents, and again, there is a sense that this is in 'violation' of some 'natural law'. Even i the case where the resulting offspring are capable of reproducing, we have the problem that those offspring may harbour some as yet undetected anomaly that would not have occurred had the reproduction of the parents been conducted au naturel. Hence the ire that is aroused among some in the hobby with respect to Flowerhorns. The reader may take a different position than the one stated above, but be advised that this is a strongly held view among numerous aquarists, and that the Flowerhorn is a fish whose existence has resulted in considerable polarisation of attitudes - there seems to be precious little 'middle ground' between the advocates of these fishes and the opponents.

So, what exactly, IS a Flowerhorn? Before answering that, however, we need to understand why these fishes, which arouse such ire in some aquarists, are popular among others.


Flowerhorns, the above notes on opponents notwithstanding, have their devotees. A particular section of devotees can be found in the Far East - most notably in cultures with a historical record of Chinese philosophical and aesthetic influence. Chinese aesthetics has, of course, been a driving force in the development of the Goldfish over at least two millennia, and also influenced the development of Betta splendens as an aquarium fish, so it should come as no surprise to learn that the Far Eastern view of the Flowerhorn contains its own differences from the Western prespective.

The Flowerhorn is referred to in the Far East by the term Luo Han, which is a Chinese phrase encapsulating the Buddhist concept of Arhat. This Sanskrit word describes the state of enlightenment attained by one who has mananged to eschew the material world as completely as possible, and devote oneself to the spiritual. Assistance in the path of development toward this goal is, needless to say, considered a worthy aim in those societies in which Buddhist or Confucian influences are strong, and so, the association of these fishes with such concepts, and in particular the Chinese view that these fishes are 'lucky' or 'auspicious' has fuelled their popularity among people with the requisite cultural background. The consequence of this is that the Flowerhorn has a ready market in the Far East, with people being prepared to pay large sums of money for these fishes, and in particular, for those fishes whose markings have an association with the talismans of Chinese or other Far Eastern spiritual thought. Hence the drive to produce fishes whose body markings, for example, resemble certain revered symbols of Kanji script, or fishes whose colours are thought to be in harmony with various other spiritual concepts deeply revered in Far Eastern societies. While those of a sceptical outlook may find it dificult to reconcile such ideas with the actual mechanics of Flowerhorn production, the person writing out the large cheque in a Hong Kong fish dealer's may equally find the sceptic's viewpoint baffling.

So, after all that, what on earth IS a Flowerhorn?


Ah, another of my favourite words. Familiar from the world of antiques, 'provenance' in the world of fishes means that you have a reasonable degree of knowledge about the nature of the fishes in your aquaria. In this case, 'provenance' includes some basic knowledge of the kind of ancestral stock of the fishes.

Here, however, is where the prospective or actual Flowerhorn owner is in something of a quandary. The commercial breeding outlets that produce Flowerhorns tend to keep the breeding details a closely guarded secret. Having spent a fair amount of this article expounding upon the reasons for the popularity of these fishes in the Far East, it should come as no surprise to learn that the prices Flowerhorns command in some markets are considerable, and as a corollary of this, the producers of Flowerhorns are not about to divulge the means by which they produce their expensive fishes, for that would defeat their commercial objectives. There would be little point in you spending $1,000 upon a prize specimen from a Far Eastern market if the 'recipe' fell into your hands and allowed you to produce the same fish for the price of a few cheap Cichlid parents and some time waiting for the fry to mature!

As a consequence, the aquarist is, in general, left to guess what fishes contribute to the ancestry of any particular Flowerhorn. Certain Cichlid species that have been reputed to form the basis of Flowerhorn ancestry include (and this does not even pretend to be a complete list):

Amphilophus citrinellus
Amphilophus festae
Amphilophus labiatus
Amphilophus trimaculatum

Needless to say, these fishes are well known to Cichlid keepers as large fishes with very strongly developed territorial instincts and a willingness to assert 'property rights' to the extent of launching into lethal combat if placed in an inappropriate aquarium setting, therefore any hybrid offspring from such parents are likely to inherit a similarly feisty temperament. The experience of several Flowerhorn keepers is that this is, if anything, an understatement - if the parent fishes are volcanic in temperament, then some of the Flowerhorns resulting from the parent fishes are positively pyroclastic, with an ability to 'go ballistic' in the aquarium that should make all but the most dedicated fan of large, aggressive Cichlids wary of taking one on board - as if the large price tag some specimens command did not act as sufficient deterrent to anyone other than the seriously dedicated owner to begin with.


So, for the aquarist that DOES decide to take a Flowerhorn on board, what are the maintenance requirements?

In common with other large, strongly territorial Cichlids, the principal requirement is space. LOTS of it. "Think of an aquarium size, then double it" is probably a safe procedure with Flowerhorns because their territorial demands are considerable to put it mildly. Even in a setup that most experienced Cichlid keepers would consider adequate to house a community of big, boisterous fishes, chances are that a Flowerhorn will demand the entire aquarium to itself. Furthermore, the tendency of some large Cichlids to solve any perceived "overcrowding" and undue intrusion of 'real estate' competitors by exterminating the competition is magnified in the Flowerhorn, in some cases to a frightening extent, and the owner had better be prepared for the very real possibility that even a colossal aquarium housing a Flowerhorn could end up as a 'species' aquarium for the Flowerhorn alone even if it started with other occupants, as the Flowerhorn dispatches its rivals with gruesome efficiency. In fact, it is even possible that two Flowerhorns of different genders may only be compatible long term in the same aquarium if they are kept from attacking each other by a very sturdy divider.

Furnishings for a Flowerhorn aquarium are likely to fall into the category of furnishings for other large Cichlids, though if the Flowerhorn proves to be completely intolerant of any other fishes in the aquarium, breaking up 'lines of sight' to diminish aggression will cease to be an issue. The safest way to proceed is to assume that the fish WILL demand exclusive rights to the whole of the aquarium, then furnish it with sturdy, large-Cichlid style furnishings that will hopefully escape being dismantled. The wise aquarist will also take measures to ensure that various life support technological fittings are protected from undue attention, so that for example, heaters are shielded from the possibility that the Flowerhorn may try to test their edibility by biting through them, or (as can happen with some Guapotes) that the Flowerhorn will find it amusing to launch the heater out of the aquarium like a Polaris missile being shot from a submarine ...

Feeding should, in the main, present few problems. Any meaty food will be devoured eagerly, and the chances are that the aquarist's main problem will fall into the realm of curbing the fish's appetite so as not to overload the biofilter. It should be obvious that a large (30 cm and above) specimen with a hearty appetite will require top quality filtration in addition to a large water volume in which to live.


Breeding? Well, the aquarist who acquires a male and female Flowerhorn may wish to try this. However, given the temperament of many specimens, this is likely to be an even more fraught experience than with several other big, bad tempered Cichlids. A divider for introductions may be needed on a full time basis, and there is the real possibility that the male and female will only ever be able to spawn with a divider between them preventing the reproductive act ending in murderous violence. Some aquarists, seeing the price tag associated with their fishes, may consider producing their own baby Flowerhorns as a profitable venture, but given the complications involved in their commercial production, such dreams may prove unrealisable. Not least because the fry may begin culling each other at an early age - indeed, the fry may require individual rearing aquaria, turning the venture into a costly exercise that only yields any kind of income after a LOT of prior investment and hard work.


Ultimately, owning a Flowerhorn is, for quite a few aquarists, not merely a question of expense. Ethics seems to loom large whenever the word 'Flowerhorn' is mentioned, and as described above, attitudes become readily polarised by the mere existence of this fish. Those aquarists who are not unduly troubled by such issues may feel free to acquire a Flowerhorn, but they should be advised in advance that [1] the unknown parentage is likely to mean that variation between individuals will be considerable [2] the fishes will be expensive to buy initially [3] the fishes are likely to be expensive to house because of their disproportionate territorial requirements, and [4] ownership of a Flowerhorn could lose the aquarist some friends among those whose aversion to the fish is particularly strong. For these reasons, acquisition of a Flowerhorn is best left to the dedicated keeper, and for that matter the dedicated wealthy keeper in the case of some of the specimens offered for sale.