Species IUCN · Data Deficient (DD)

Ayu

Plecoglossus altivelis, (Temminck & Schlegel, 1846)

marinebrackishfreshwater

About Ayu

The ayu sweetfish (Plecoglossus altivelis), ayu (アユ, 鮎, 年魚, 香魚) or sweetfish, is a species of bony fish. It is the only species in the genus Plecoglossus and family Plecoglossidae. It is a relative of the smelts and other fish in the order Osmeriformes.

Native to East Asia, it is distributed in the northwestern Pacific Ocean along the coast of Hokkaidō in Japan southward to the Korean Peninsula, China, Hong Kong and northern Vietnam. It is amphidromous, moving between coastal marine waters and freshwater lakes and rivers. A few landlocked populations also exist in lakes in Japan such as Lake Biwa. Original wild populations in Taiwan became extinct in 1968 due to pollution and present extant populations were reintroduced from Japan in the 1990s.

The name "sweetfish" was inspired by the sweetness of its flesh. In reference to its typical one-year lifespan, it is also written as 年魚 ("year-fish"). Some individuals live two to three years. The ayu is the prefectural fish of Gunma Prefecture and Gifu Prefecture.

Humans & conservation

The ayu is highly prized for its flavour, mostly consumed in East Asia. Its flesh is distinctively sweet, with "melon and cucumber aromas". The main methods for obtaining ayu are by means of fly fishing, by using a fish trap, and by fishing with a decoy which is known as ayu-no-tomozuri in Japan. The decoy is a living ayu placed on a hook, which swims when immersed into water. It provokes the territorial behavior of other ayu, which assault the "intruder" and get caught.

The ayu is also caught by cormorant fishing. The practice on the Nagara River, where Japanese cormorants (Phalacrocorax capillatus) are used, draws visitors from all over the world. The Japanese cormorants, known in Japanese as umi-u (ウミウ, "sea-cormorant"), are domesticated birds trained for this purpose. The bird catches the ayu, stores it in its crop, and delivers it to the fishermen.

Part of

Smelt

Where to see it

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