The Koi fish is known for being a symbol of strength, courage, and patience. Known for swimming against the current, the Koi fish symbolizes what it takes to overcome obstacles and challenges that are in your path. Koi fish were believed to originate from rice farmers domesticating carp in China during the 4th century. The breeding between the colorful types of carp resulted in the diversity of Koi fish you see today.
Koi fish do not only have historical and spiritual importance but their biology is fascinating as well. They typically grow between the sizes of 24 to 36 inches but, they can grow up to 52 inches! That is the size of an average 10-year-old boy! They also have extremely long lives for fish. They have the chance to live up to 100 years with the typical range being somewhere between 25 to 35 years. Even though these fish are cold-water fish, they benefit heavily when being placed in waters above 55 degrees Fahrenheit. This is because Koi fish that are in waters below 50 degrees Fahrenheit for long periods can begin to develop a weakened immune system. This can reduce the lifespan of the fish as well as decrease overall health.
One of the coolest things about Koi fish is what happens to them when they are placed back into the wild. Since Koi fish is a relatively new species in comparison to other animals, they still have all the genes of their ancestor carps. After a few generations of being left in the wild, they will no longer be identified as a Koi and revert to an Amur Carp.