Koi

COMMON NAME: Koi.

SCIENTIFIC NAME: Cyprinus carpio.

DESIGNATION: Coldwater.

GEOGRAPHICAL DISTRIBUTION: Originally fromthe regions around the Black Sea and theAegean basins (particularly the Danube), thisspecies has been introduced into countries allover the tropical and temperate areas of theworld, largely as a food fish. Koi are highlycoloured varieties of the species which are notfound in nature and represent the only type ofC. carpio kept in any significant numbers byhobbyists.

SIZE: Up to about 39 in (1 metre) in well-maintained ponds - much smaller than thisin aquaria.

WATER PREFERENCES: Will tolerate a widerange of water conditions and temperaturesbut will experience stress during prolongedperiods at high temperatures (around 28°C/82°F and above).

DIET: Koi are omnivorous, which means thatthey will eat both animal and plant-basedfoods. Both must, therefore, be provided.Since only small specimens are suitable foraquaria, and these are invariably immature,growing individuals, the diet should contain afairly high concentration of protein (about 40percent - adults require less). There arenumerous high-quality commercial foodswhich have been specifically developed forKoi.

BREEDING: Koi require large ponds (pools) forbreeding. Provided with the right conditions,they will spawn in a similar fashion to Goldfish. Aquaria are totally unsuitable forbreeding purposes.

DESCRIPTION: Koi, like Goldfish,are very efficient water foulers. Therefore,despite their undoubted hardiness, a goodfiltration system is essential. In addition, thelarge size to which Koi can grow dictates thatonly very small or juvenile specimens can beadequately catered for in most aquaria.

The appearance in recent years of largenumbers of small, inexpensive, non-pedigreeKoi has led to a marked increase in thepopularity of this fish among aquarists.Previously, interest was almost exclusivelyconfined to fishkeepers with large ponds. Itmust be borne in mind, though, that smallKoi bought for aquaria are likely to outgrowthe available space sooner or later andprovision for this should, obviously, be made.The best Koi have traditionally originatedin Japan, a situation that is likely tocontinue, at least, for the forseeable future.Because of its origins Koi-keeping hasdeveloped its own vocabulary, consisting ofJapanese terms used to describe the different(and numerous) varieties. A few of the mostpopular are:

Kohaku A white fish with orange/red bodymarkings. Sanke A tri-coloured fish in red, white andblack. Two forms are generally described:

(i)Taisho Sanke, which is mainly white withsome red and black; and

(ii) Showa Sanke,which is mainly black with some red andwhite. Ogon A single-coloured fish, usually white,yellow, golden, orange or red. Shiro Bekko A white fish with blackmarkings. Shiro Utsuri A black fish with whitemarkings.
Ki Bekko A yellow fish with black markings.Ki Utsuri A black fish with yellow markings.Aka Bekko A red fish with black markings.Hariwake A white fish with a metallic sheenand silver or gold markings.

Such brief descriptions give only theminimum information about a trulymagnificent range of fish, and do little justiceto the sophisticated world of top-flight Koi-keeping. There seems to be no end to thepossible permutations, especially when thebasic colour patterns can be superimposedwith silver or mother-of-pearl lustres (Gin -with a hard 'G' - and Gin Rin, respectively),pine-cone scales (Matsuba), separate rows oflarge scales running down the back, or evenno scales at all (Doitsu), and so on.

Anyone wishing to go into the fascinatingworld of Koi in detail should consult thespecialist literature (see Bibliography as astarting point) and join a Koi society.
As with Goldfish, highly competitive Koishows are organised at regional, national andinternational levels, where standards andjudging demand the highest degree ofexpertise. Not surprisingly, the very best Koicommand astronomical prices.