KOI 101

Koi fish are a great hobby. Here are some interesting facts.

Why Koi ?   History    Sexing    Quality    Growth Rates

Why Koi ?

Koi fish are a great hobby. They also help you to relax and relieve stress. Koi are
particularly fun to watch eat. Although Koi will eat many natural food sources such as
algae and other natural pond residents, the greatest pleasure for many Koi keepers is in
feeding them.

They are truly hogs. They look like piranhas at feeding time, churning the water, jumping, and I have seen some perform like porpoises, walking along the water's surface on their caudal fin. Once you hear the sucking sound of Koi sucking down food you'll never forget it. They remind me of water polo players who are about to get to the ball when suddenly other players from behind swim up and over them pushing them under the water. Koi will even swim up on lily pads to get trapped food.

They are very smart, and can be trained to eat out of your hand. They are by nature bottom rooting and feeding carp. They quickly learn to eat floating dry food. I have found floating feeding rings add to the enjoyment. They learn to "hang out" around the feeding ring.

Koi are very expensive when they are full size (30 to 40" in 5 to 8 years), but as small fish they are only a few dollars each. The prices are listed on our site for sale can live for 30 to 40 years, and even longer.

Many Koi ponds can come close to breaking even by selling off the excess Koi after they
have grown larger. On the other hand, an investment of $500 to $1,000 of small Koi each year for 5 years, could possibly yield 1,000 or more Koi worth more than $1,000,000. Large size Koi can easily be worth $1,000 each, great quality Koi can bring $250,000 each or more, but are rare.

RETURN TO TOP

Koi History

Today Koi are bred in every country and considered to be the most popular fresh-water
ornamental pond fish and are often referred to as being "living jewels" or "swimming
flowers".

Koi are a variety of the common carp, Cyprinus carpio. Carp fossils have been discovered in South China dating back about 20 million years. Some varieties are known for their hardiness, which records claim can live for long periods of time if simply wrapped in wet moss continuously kept damp.

Some authorities believe Koi originated in Persia and spread throughout the ancient world.

Koi, or nishikigoi - Japanese for "brocaded" carp - were first described in writing from a
Chinese book written during the Western Chin Dynasty, 265-316 A.D. At that time they
were described as white, red, black and blue.

What happened to Koi from the 2nd to the 17th century is still being investigated, but
many suspect Koi were gradually spread around the orient, and possibly even via trade
caravans to or from the middle east.

Koi breeding in Japan is recorded from the 17th century in the rice-growing region of the
Niigata Prefecture. They were originally bred as protein food supplements.

RETURN TO TOP

Koi Sexing

It is difficult to tell the sex on younger Koi, it gets easier as they get older. Females tend to have rounder bodies and rounder pectoral fins and their fins tend to be somewhat smaller. Males are sleeker, with more pointed pectoral fins, and their fins tend to be larger. Others claim the colors of males are more brilliant. Older males have a sand paper like raspiness on the gill plates, and some claim you can also feel a roughness if you lick your tongue across the front of the pectoral fin. If you try this let us know!

The easiest way is when there is a particularly aggressive male chasing the females
relentlessly, you look for other males chasing the same now identified females.

RETURN TO TOP

Koi Quality

40% The most important quality of good Koi is SIZE!! Like a Sumo wrestler bigger is
better. You can't always control size (see Koi growth rates) since you may have Koi that were not well fed at the proper times, or your pond may be too small, or the water quality, oxygen levels or temperature may not be ideal or the Koi may be weak and sick from parasites, bacterial, viral or fungal infections.


Part of size is shape and volume. Symmetry in shape is very important i.e., the head,
mouth, eyes, fins, etc. Any deformities are marked off. In most shows Koi are grouped by size and then judged within that size grouping.


Although the "Grand Champion" will usually be picked from the largest size group, within
a given size group pattern becomes the next most important criteria 20% Pattern (in one color Koi obviously there is no pattern) unique patterns are desirable lightning patterns are even better crisp edges to patterns are preferred lack of blemishes are important no "dirty" face, head, nostrils, etc. in Doitsu the scale pattern should be symmetrical.


20% The next quality point is color depth and purity of color is very important a delicate
creamy white with a depth to it a deep black (the old adage is black comes - and expands) a pure red (the old adage is red goes - and contracts) the depth of lustre is sought after especially in metallic varieties.


20% The next quality point is their star celebrity elegance intelligence and personality
social behavior and graces regal presence while swimming around pond.

RETURN TO TOP

Koi Growth Rates

Some Koi can get to be a meter long which is 100 centimeters, 3.28 feet or 39.37 inches. However, modern Koi average closer to 80 centimeters (31.5 inches), which is still a long way from the 1/16th inch of the newly hatched Koi. Using the Ludwig von Bertalanffy growth equations (1938) it can be shown that generally Koi reach about 50% of their final adult length at 24 months, 95% at 10 years, and 99% at 14 years. Obviously their size depends on the environmental conditions such as pond size, oxygen concentration, water temperatures, water quality, amount and type of food, and length of the growing season. Vitamins, exercise, and lack of stress may also play an important role.


In the mid 1980's in Lake Biwa in Japan they netted a 6.5 foot Cyprinus carpio, but it died in a public aquarium in Kyushu. There are other examples of carp reaching enormous
sizes in large bodies of water. The mahseer, a member of the carp family Cyprinidae,
genus Barbus, typically reaches 6.5 feet and a weight of 200 pounds. It is found in
Southeastern Asia. Although that is a big fish, it is not as big as the wels, also called
WALLER (species Silurus glanis), a large, voracious catfish of the family Siluridae, native to large rivers and lakes from central Europe to western Asia. One of the largest catfishes, as well as one of the largest of European freshwater fishes, the wels attains a length of about 4.5 m (15 feet) and a weight of 300 kg (660 pounds).


Koi claimed to have reached 2 meters (6 feet) in length, and the oldest to have reached
the age of 230 years, passed down from generation to generation. Most modern Koi are
considered special if they reach 1 meter in length, and average age from 40 to 60 years.

Back to our favorite Koi. It appears that depending on their age and under optimum
conditions Koi can grow over 2 centimeters (almost an inch) per month or faster,
remember there are 2.54 cm in an inch.

RETURN TO TOP