Jump to main content
梅園魚品図正より「鰻」 / 国立国会図書館所蔵

Unagi (Eels)

The unagi (eel) belongs to Anguilla genus, Anguillidae family, Anguilliformes order, Actinopterygii subclass, Osteichthyes superclass. They are found throughout Japan.

The unagi (eel) belongs to the Anguilla genus, Anguillidae family, Anguilliformes order, Actinopterygii subclass, and Osteichthyes superclass. Other than inhabiting rivers and lakes throughout Japan, eels are widely distributed throughout East Asia, including the Korean Peninsula. Eels eat small fish, crabs, shellfish, and shrimp. Adult eels grow to about 60 cm long, although some measure up to 1 m in length. 

Adult eels live in rivers and estuaries, but spawn in the sea. Although a detailed ecology is unknown, recent studies have shown that eels spawn in the Mariana Trench, returning to the waters near Japan after their long journey.

Larvae that hatch from May to September are called 'larva of Leptocephalus', and are the shape of willow leaves. When the Leptocephalus reaches a length of about 6 cm, it metamorphoses into a cylindrical fry, called a glass eel. Glass eels gather around estuaries between October and February, then swarm up the river, change their body color and become adults. They inhabit rivers and ponds for five to ten years and then move to the sea to lay eggs. 

Japanese eel numbers are decreasing due to issues such as changes in the marine environment and excessive fishing. They are classified as endangered by the Ministry of the Environment and the International Union for the Conservation of Nature and Natural Resources.

Related People, Things and Events

Books

Related Works

Japanese Traditional Eel Fishing Tools

Japanese eel specimens and other members of the unagi family

Videos

Institutions Holding Related Materials

  • 東京都台東区に所在。ウナギの一生に関する展示が行われている。

  • 静岡県浜松市に所在。ウナギとふれあえるブースがある。

  • 静岡県静岡市に所在する国内のウナギ養殖の生産者団体。全国のウナギ生産量などの統計資料を掲載している。

  • 水産庁の公式ホームページで、ウナギに関する生産状況や供給量の推移など最新情報を掲載している。

References

  1. 東京書籍