| Like the goldfish, Koi are a domesticated variety of | | | | water. Temperature plays a role here as well |
| the carp. In fact, the word Koi comes from the | | | | because cold water can hold more dissolved oxygen |
| Japanese word meaning "carp". An interesting side | | | | than warm water does. In a still pond oxygen is |
| note is that the same sound means love or affection | | | | taken up by water at the surface, so when you |
| in Japanese, so Koi have become symbols of love in | | | | factor in the need to have a pond at least three feet |
| Japan. One time at which this can be seen is during | | | | deep and you can see that a large volume of water |
| the annual Boys Festival. A hallmark of this festival is | | | | is necessary. |
| the koi streamers that are attached to the | | | | When I started out with aquarium fish in the 1950s |
| ridgebeams of the houses. | | | | air pumps were quite expensive and many tanks |
| The first record of carp being bred for color was in | | | | were set up without any artificial aeration. In those |
| the Sung Dynasty in China around the year 960. Koi | | | | days the basic rule of thumb stated that you needed |
| as we know them today were developed in the city | | | | one gallon of water for every inch of fish. |
| of Ochiya in Japan during the 1820s. By the start of | | | | Deep water aeration via pumps and airstones is a |
| the twentieth century the main color varieties had | | | | good way to infuse more oxygen into the water and |
| been set. | | | | also does away with the stagnant layer that often |
| Although Koi and goldfish are both varieties of carp, | | | | exists at the bottom of a pond. |
| goldfish were developed from the prussian carp while | | | | The other way of increasing the oxygen in the water |
| Koi are derived from the common carp. Goldfish are | | | | is by means of a waterfall. The falling water is |
| actually the older breed. They were brought to Japan | | | | picturesque, sounds good, and the roiling of the |
| from China in the 1600s and introduced to Europe in | | | | water allows it to absorb more oxygen than it |
| the seventeenth Century. Goldfish are generally one | | | | otherwise would. |
| solid color, either red, black or occasionally white. Koi | | | | One of the good points about Koi being cold water |
| come in many more colors including, red, orange, | | | | fish is that they can be left out in the winter. In fact, |
| yellow, black, white, silver or even blue or green. | | | | there have been cases of carp being frozen in solid |
| However the colors of Koi are not only determined | | | | blocks of ice and simply picking up where they left |
| by heredity. Other factors such as the environment | | | | off when it melted. When the water temperature |
| that they live in and the diet they eat can also have | | | | decreases, Koi sink into hibernation, becoming less |
| an effect. the color of Koi. | | | | and less active. |
| The basic nature of Koi is that they are cold water | | | | Unfortunately, they can still eat under these |
| fish and this fact must never be forgotten. Their | | | | conditions. Although they are able to eat, their |
| pond should be at least three feet deep so that a | | | | digestive systems have shut down for the winter |
| good temperature gradient is maintained. When the | | | | and the food can rot in their stomachs and sicken |
| surface temperature of the water rises in the | | | | them. For this reason Koi should not be fed when the |
| summer the Koi will go deep in search of the cooler | | | | temperature of the water has fallen below fifty |
| water at the bottom of the pond. If the pond is | | | | degrees fahrenheit. |
| large enough, a tree or two planted beside it can | | | | Outdoor ponds are prized for their scenic beauty and |
| provide cooler shady spots where the fish can loaf. | | | | for the sounds of rippling water that sooth our |
| The drawback to this is that the trees can drop | | | | senses, but they really need the flashing vibrant color |
| leaves and other material that are unsightly and can | | | | of ornamental fish like the Koi to complete the vista. |
| clog filters and spillways. | | | | A pond stocked with Koi brings peace to the mind |
| The biggest single factor that determines how many | | | | and color to the eye. What more could you ask for? |
| fish can live in a pond is the oxygen content of the | | | | |