it is either dying of deadly fungi or just getting old
Yes they do.
it is starting to die.
Koi fish can lose their color due to stress, poor water quality, or a lack of proper diet. Additionally, environmental factors such as excessive sunlight exposure or high levels of ammonia in the water can also cause koi fish to lose their color.
Koi fish Koi fish
The Japanese for Koi is nishikigoi.
There are many ways in which scales assist a fish. The easiest one to explain and probably the most accurate to answer your question is that the scales are smooth and provide an aerodynamic facade, which helps them swim more efficiently.
Koi fish can live in almost any country. Koi are thought to be originally from Japan. Many people have outdoor fish ponds in which Koi are the dominant fish.
Fish naturally loose their scales, but if your fish are loosing many scales at once, its not natural. Goldfish may loose their scales if they are stressed. If you get another fish, try medicating the tank with something like MelaFix for a while to prevent that from happening.
a fish, a koi carp
because it is fish
In Japanese, koi fish is written as "鯉" (koi). The character for "koi" represents the colorful carp fish that are traditionally kept in ponds for their vibrant colors.
Koi fish usually have two eyes.