Amur catfish

What it is

This large catfish has a robust, elongated body with smooth, scaleless skin. Its colour ranges from olive-green to yellowish-brown, marked by irregular white spots on the sides and a white stomach. The head is broad and flat, featuring a terminal mouth filled with small, sharp teeth. Distinctive long barbels extend from the mouth corners. Adults have one pair of maxillary barbels longer than the head and one shorter pair on the lower jaw. Juveniles possess an extra pair of lower barbels that disappear as they mature.

Where it lives

The species inhabits freshwater catchments across East Asia. Its distribution includes China, Japan, the Korean Peninsula, Taiwan, the Russian Amur Basin, and northern Vietnam. It prefers slow-moving rivers, irrigation canals, and lakes with dense grass cover. These environments provide shade and shelter, suiting its resting habits. The fish thrives in water temperatures between 20 and 27 degrees Celsius. It may migrate downstream to find suitable environmental conditions if displaced.

How it lives

As a nocturnal predator, this catfish hunts at night and rests in caves or shaded areas during the day. Its poor floating ability, caused by bladder enlargement, restricts it to swimming near the bottom. It feeds on aquatic insects, crustaceans, and smaller fish, expanding its mouth to swallow larger prey. Natural predators include monitor lizards, otters, birds of prey, and other fish. The species adapts well to various freshwater habitats provided there is adequate cover and water flow.

Breeding and life cycle

Reproduction occurs in warmer months, typically spring or early summer, often following rainy periods. Females release dispersed eggs to reduce juvenile mortality. Fertilised eggs have a distinct green hue, with larger eggs showing higher survival rates. Hatching takes about 27 hours in warm water, extending to 48 hours in colder conditions. Populations show a sex ratio skewed toward females. Mating rituals in some groups, such as the Biwa population, involve chasing and enfolding by the male.

Fish and people

This fish holds commercial value in eastern Japan and serves as a protein source in mountain villages. Aquaculture is common, though historical issues with cannibalism among fry required new techniques to boost production. Anglers target it in rivers and lakes across East Asia for sport due to its large size. While widely farmed, natural populations have declined in recent decades. It remains a significant part of local diets and recreational fishing activities in the region.

Status and threats

The International Union for Conservation of Nature lists the species as Least Concern across its entire range. However, regional assessments indicate pressure on local stocks. The 2012 Taiwanese Red List of Fresh Water Fishes categorises it as Near Threatened. Natural populations have decreased significantly over the past few decades, prompting reliance on farming. Conservation efforts focus on managing wild stocks while supporting sustainable aquaculture practices to meet demand.

Questions people ask about Amur catfish

Good reading and sources

• Amur catfish on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data