Koi

Where it lives

Koi are domesticated and live almost exclusively in ornamental ponds and water gardens. Wild “feral koi” descended from escapees can persist in warm temperate ponds and rivers worldwide, often reverting toward the muddy bronze of their carp ancestors.

How to recognise it

The body plan is that of the common carp — long dorsal fin, two pairs of barbels, large scales. What sets koi apart is color: solid white, red, orange, black, blue, or yellow, alone or in patterned combinations like kohaku (white with red blotches), taisho sanke, and showa. Some varieties are scaleless (doitsu).

Diet & behavior

Koi are omnivores that hand-feed readily on pellets, vegetables, and live insects. They are highly social, intelligent, and long-lived — well-cared-for koi commonly reach 30 to 60 years.

Fisheries & Conservation

Globally Least Concern as a domesticated form. Competitive koi keeping and the global ornamental fish trade together support multi-billion-dollar industries, with the most prized show fish selling for hundreds of thousands of dollars.