Nishikigoi basically have the same ecology as Koi. They have high adaptability and are easy to raise. Compared to other animals, they are very friendly and will feed off the hand when they get used to humans. In recent years, they are loved as pets from worldwide Koi lovers.

Environment

Nishikigoi are temperate freshwater fish with high adaptability and can adapt to water temperature of approx. 47 to 95 degrees F, but optimal temperature is approx. 68 to 77 degrees F. Sudden temperature change of more than 9 degrees is undesirable.

Feed

Nishikigoi are omnivorous, strong fish and will eat almost anything humans eat. When feeding them off-the-shelf feeds, one need’s to select the feed that is fit for one’s purpose. For example, there are feeds that enlarge the body or that bring out beautiful colors.

Physiology

Nishikigoi are spindle-shaped and have a pair of barbells around the mouth. At the tip of the barbells, there are nerve cells that detect major tastes. The barbells play a very important role as they are used for tactile senses as well. They do not have so-called teeth, but near the throat they have 5 pairs of pharynx teeth in 3 lines, and these are used to grind and ingest the food. The pharynx teeth are very powerful. Nishikigoi can swallow pond-snails with their shells, break the shells, eat only the flesh, and finally spit out the shells. Nishikigoi have no stomach, so what they eat go directly from the esophagus to the bowel. They cannot keep food, so the best way to feed them is to give small portions 3 to 6 times a day

Growth and lifespan

Male Koi mature at 2 years and females at 4 years of age. Their average lifespan is 70 years which is dramatically longer than other animals. The oldest living Koi in Japan was born in 1751. She was a Higoi named “Hanako” and lived for 226 years.


In Japan, families with boys celebrate May 5th, Children's Day, with "Koinobori" (carp streamers) to wish for the boy's healthy growth.