Koi aren't lightweights either; they typically tip the scales around 35 pounds (16 kg), and experts advise filling a pond with about 500 to 1,000 gallons (1,893 to 3,785 liters) of water per each ...

A koi's color cells sit at different depths in the skin, some right near the surface and some deeper in, which ultimately determines how bright the fish appears. The brighter the fish, the bigger ...

Koi diplomacy is back with Japanese nishikigoi ... authorities have agreed to resume imports of these vibrantly colored fish, although the reason for the suspension remains unclear.