Masu salmon
Amazing fact
River-resident masu salmon line up along the current in order of body size.
国立環境研究所 侵入生物データベース
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An illustration based on the real animal.
A little discovery to share.
River-resident masu salmon line up along the current in order of body size.
THE REAL WORLD
The real Masu salmon
- Scientific name
- Oncorhynchus masou
- Japanese name
- サクラマス（ヤマメ）
- Group
- Freshwater animals
- Order
- Salmoniformes
- Family
- Salmonidae
- Genus
- Oncorhynchus
Fish that grew up at sea and returned to the river are called sakuramasu; those that stay in the river, and young fish before they go to sea, are called yamame. The satsukimasu (amago) is regarded as a subspecies of this species.
A member of the salmon family; some go down to the sea to grow, while others spend their whole lives in rivers.
While growing up in the river it has a row of dark marks along its sides; before heading to the sea, the marks fade and its body turns silvery.
Fish that grew up at sea start swimming up rivers around cherry-blossom time, spend the summer in the river and lay their eggs in autumn.
How the Masu salmon lives
Young fish often eat springtails in shallow, slow-flowing water at first. They also eat aquatic insect larvae and insects that fall into the water. At spawning, a pair stays close together and opens their mouths wide.
国立環境研究所 侵入生物データベースBasic data
- Size
- Body length: 30–60 cm水産研究・教育機構
- Diet
- Aquatic insects, fallen insects and others国立環境研究所 侵入生物データベース
- Range
- Kamchatka, eastern Korean Peninsula, Sakhalin and Japan国立環境研究所 侵入生物データベース
- Conservation status in Japan
- Near Threatened (NT)Assessed as Oncorhynchus masou masouMinistry of the Environment of Japan, Red List 2020
Where the Masu salmon has been recorded
Records: GBIF.org (CC0 and CC BY 4.0 records, retrieved 2026-11-07). Map: Natural EarthSee the records on GBIF
Watch wild animals from a distance. Do not touch or feed them, and take care of the places where they live.
Names around the world
- 日本語
- サクラマス（ヤマメ）
- 简体中文
- 樱鳟
- 繁體中文
- 櫻鱒
- 한국어
- 송어
- Español
- Salmón japonés
- Français
- Saumon masou
- Deutsch
- Masu-Lachs
- Português (Brasil)
- Salmão-japonês
- Italiano
- Salmone giapponese
- Tiếng Việt
- Cá hồi Masu
- Русский
- Сима
- Türkçe
- Japon sombalığı
Names come from Wikidata and iNaturalist records. Where a language has no recorded name, we use the scientific name.
Sources and how we check
- 国立環境研究所 侵入生物データベース — ヤマメChecked: 2026-11-03
- 水産研究・教育機構 — 日本のサケ科魚類Checked: 2026-11-03
- Ministry of the Environment of Japan, Red List 2020Checked: 2026-11-07
We check each fact against its source. The illustrations simplify how the real animal looks.
The classification (class, order, family, genus) follows Wikidata records, checked against GBIF. Classifications can change as research goes on.
The basic data are the values given in each source. They vary with how the animal is measured, whether it is male or female, and whether it lives in the wild or in captivity.
The conservation status in Japan is the category in the Red Lists of the Ministry of the Environment of Japan, which assess the risk of extinction for wild animals in Japan.
This page was translated from the original Japanese with the help of AI.
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