Indeed, the ghost koi is not recognised by koi enthusiasts as a koi variety and would certainly not be found in the pond of a koi purist. No wonder therefore that the unprecedented rise of the ghost's popularity has not been widely or 'officially' acknowledged over the past few years and that its poor coverage in pond and koi publications does not correspond to its popularity in the UK.
What are ghost koi and what makes the nation's favourite koi variety so popular?
It is not simply the ornamental trade that is so obsessed with this variety. Over the last decade, ghost carp (notice the subtle change in the name) or 'ghosties' have also shot to the top of the list of most carp anglers. Having stalked common and mirror carp in lakes for many years, the introduction of ghosties into the same waters has added a new flavour to the angler's catch, adding another variety and an unusual splash of colour to the angler's catch.
Israeli coloured Ghost koi and ghost carp are the same fish and are carp hybrids, the result of a cross between a metallic koi and a common carp. NB This is not a hybridisation between species but between varieties of the same species producing fertile offspring.
Recognising that koi are the same species as carp (Cyprinus carpio) and it is through man's selective breeding that koi occur in an infinite array of colours and patterns, it is not surprising that a cross between metallic koi and common carp produces viable offspring - ghost koi. These offspring exhibit 'hybrid vigour' where the hybrids outperform the parents' growth, fertility and health.
The record carp in the UK is over 55lbs. Ghosts have reached 30lb in the UK (so far) and there is no reason if given the time and space, why they should not get that large in similar conditions. They certainly have the ability to outgrow koi.
Ghosts can also become exceptionally tame, coming to eat from your hand. This 'friendly' nature is often their most appealing feature as they rush toward prospective purchasers in retail stock tanks asking to be taken home and put in your pond.
Consequently ghosts can be very rewarding pond fish. They are undemanding in terms of their husbandry but will benefit from a large pond. While maintaining some ornamental value, they do not suffer the shortcomings and limitations of other ornamental varieties and often endear themselves to pondkeepers as a very rewarding fish for their confident character and exceptional value and growth. No wonder they are the UK's favourite koi variety.
Care Tips .... There are very few care tips and nothing specific to the ghost koi.
Keep them in as large a pond as possible and treat them as a pond fish rather than a koi. They do not require a premium koi diet with colour enhancers but a well balanced pond fish diet will be sufficient for this undemanding fish. They can be fed earlier in the Spring and later in the Autumn than koi without risking associated health problems experienced in purer inbred
As ghosts will readily consume quantities of food, the pond must have effective means of removing solids to maintain clarity coupled with effective biofiltration to breakdown toxic metabolic by-products. I.e. normal pondfish practise.
Why are ghost koi so popular?
Ghost koi offer excellent value for money. For a number of reasons they are cheaper than standard koi but this does not really make them a second-rate alternative to koi.
Ghosts are cheap to buy because compared with koi and other selected ornamental pondfish they are relatively cheap to produce. Although they are farmed in an identical way to koi, they offer a number of attractive benefits to the ghost koi farmer.
Koi breeders and farmers have traditionally passed experience and expertise down through generations to develop high quality and reliable bloodlines. When they breed from these bloodlines, only a minute fraction of the spawn reaches the market as high quality stock, commanding a high price.
By contrast, broodstock required to produce ghosts are readily available at a reasonable price without the necessary investment of time and effort over many generations. In addition, the majority of ghost offspring are marketable, and the expertise, time and expense of culling is not required on the same scale as in koi production and as more fish reach market per spawn, the unit price of each fish is greatly reduced. However, the research, experience and knowledge of which particular broodstock produce the best ghosts is essential to provide the market consistently with top quality metallic ghost koi.
As ghosts are hybrids of koi and carp, they are more vigorous than koi producing better growth and offering better disease resistance. In koi breeding, through years of selection for colour and shape, inbreeding of stock has reduced koi vigour rendering them weaker, slower growing and more susceptible to disease than their wild 'carp' ancestors. This benefits both the ghost koi farmer and keeper who experience accelerated growth and enhanced health, vigour and vitality over their 'true' koi cousins by virtue of the stronger genes passed on from the carp broodstock.
Having had experience of farming and keeping both koi and ghosts, the contrast between the husbandry of both varieties is quite stark.
Koi generally have to be treated/medicated almost as a matter of course and great attention shown to water quality and nutrition to keep them in top condition and to achieve breeding success. A testament to the ghosts vigour, disease resistance and undemanding physiology compared with that of koi.
The spin-off for the ghost koi keeper is that they can taste koi keeping but without the disease hazards feared and often experienced by conventional koi keepers. As their investment in ghost koi is likely to be less than in koi then if they lose a fish they are less likely to suffer a significant financial loss and as their requirements are less demanding, they can be kept quite satisfactorily in a garden pond environment. In fact it has been argued that ghost koi are even hardier and less demanding than goldfish.
Money can also be saved by not having to go to the expense of extensive filtration systems that many koi keepers need to install to maintain a stable and suitable water quality for their relatively frail koi.
Where ghosts are kept with koi, they often outgrow their weaker relatives, courtesy of their stronger genetic make-up. This phenomenon can also be seen in many ponds where drabber koi or goldfish outgrow and are healthier than the more visually striking and purer varieties. I.e. they retain some of the vigorous wild-type genes.
Selecting Your Ghost Koi
Be careful when selecting ghosts for your pond to take into account the sizes and natures of your existing pond fish. These vigorous and competitive fish can change a well balanced 'placid' pond into an aggressive free-for-all at feeding time. Try to buy them smaller than your existing fish. They will soon outgrow the other inhabitants anyway, but it allows your existing stock to adjust to the new ghost carp and will save you money by buying small ghosts to start with.
Personal taste dictates which ghosts you select, but shop around as a whole range of colour variants in ghosts exists. Huge quantities are consistently imported from Israel and a lot of UK bred ghosts are also on the market offering an acclimatised and short-travelled fish. Something to consider when buying.
Parts of this article should be credited to Ben Helms Book www.watergardenersbible.co.uk