Koi fish possess an unusual staying power. Some are found to have lived as long as two hundred years although their life span normally extends up to thirty five years. All varieties of Koi fish are found in outdoor ponds in almost every country around the world. Males are distinguished by their bowl-shaped anal section. Koi males are also recognized by attractive breeding spots on their head. When they breed they could spawn as many as one thousand or more eggs. Baby Koi is called ‘fry’ emerging from the eggs in about 4 to 7 days depending on the temperature of the water. The color that is so imperative to the Koi does not come up for 3 to 12 weeks after birth.
The Japanese engendered these fish out of carp mutations. Primitively they were only available in one or two colors. But with the exploration of new breeding techniques they have become available in a lot more colors and patterns. The different colors and patterns are their drawing cards from medieval time up to present.
Black Koi are raised in large ponds because of their bulk size. Their standard length is forty inches. One variety called ‘Magoi Koi’ is essentially deep bronze in color but they appear the same as Black Koi when viewed from above. They are one of the very first varieties of black mutations. Because of their unusual size Magoi blood is being exploited to make the most of growth possibilities of other species.
Another variety called ‘Karasu’ or ‘crow’ black Koi is more primitive Koi species. It has black body and black fins. This species has either a white or yellow belly.
Koi have a remarkable ability to alter their color with respect to either environmental stimulus or to adjust their diet. A drab colored Koi can alter color to a more vibrant one. One particular species of Koi that can change color conspicuously is the Matsukawabake, a usually black Koi with areas of white. It’s interesting to note that in respect to water temperature Koi fish can become entirely black or entirely white and with a consequent change in condition it can return to its original color.
The ‘Kumonryu’ or ‘dragon fish’ is deemed to be the most famous among black Koi species. It first came into attention in the early 1980’s. It has earned its so nickname ‘dragon fish’ because many believe that it has a resemblance with the shapes of dragons as depicted in historic paintings. The Dragon fish shares a harmony with another popular species of black Koi called Matsukawabake this being that both varieties can adjust color.
The wide variety of colors of Koi is one of the main reasons that bring pond owners to the Koi. It is even more driving that one can own a fish such as black Koi which can actually alter color in front of your eyes.