Koi are robust heavy-bodied fishes. Most koi average about 90 cm (about 36 inches) long and weigh about 16 kg (about 35 pounds) when fully grown. They are adaptable omnivorous cold-water fishes that consume insects, crustaceans, and other invertebrates as well as algae and vegetation.

Koi fish can reach lengths of up to 3 feet – they are one of the largest cyprinids and one of the largest fish commonly kept in backyard ponds. They generally have two barbels on both sides of the jaw and have a round snout and a toothless jaw for taking in gulps of prey. Females are larger and have rounder bodies than males.

5 Incredible Koi Facts! Here are five facts about koi fish. Japanese rice farmers started breeding koi for their beautiful colors in the 19th century. Koi have different meanings depending on their coloring. For example, the Ogon koi with its metallic silver scales is a symbol of wealth and a successful business.

Fun Facts A common misconception is that koi are large goldfish; although koi and goldfish are both domesticated from carp, they are distinct species. While carp are popular with anglers, koi are bred for ornamental ponds. Koi and goldfish are the most popular freshwater, ornamental fish throughout the world.