Translation guide
A species that humans have intentionally or accidentally moved to a new area outside its native range.
The most common and neutral way to refer to an introduced species in Japanese.
The standard term for any species introduced from another region, whether intentionally or accidentally. Used in scientific, environmental, and everyday contexts.
この池には外来種の魚がたくさんいます。
There are many introduced species of fish in this pond.
外来種が在来種に与える影響を調べています。
We are investigating the impact of introduced species on native species.
A more technical term, often used in ecology and conservation biology. Emphasizes the act of being brought in, regardless of impact.
この島には多くの移入種が定着しています。
Many introduced species have become established on this island.
Specifically refers to introduced species that cause ecological or economic harm.
The official term for invasive alien species, used in Japanese law and environmental policy. Implies significant negative impact.
侵略的外来種の駆除が急務です。
Eradication of invasive alien species is an urgent task.
Designated invasive alien species under the Invasive Alien Species Act. These are regulated by law.
アライグマは特定外来生物に指定されています。
Raccoons are designated as an invasive alien species.
An introduced species that has established a self-sustaining population in the wild.
Refers to a species that has become naturalized, often used for plants and animals that have integrated into local ecosystems.
セイヨウタンポポは日本では帰化種として広く見られます。
The dandelion is widely seen as a naturalized species in Japan.
A neutral term often used in legal or policy contexts, similar to 'alien species' in English.
A broader term that includes all non-native organisms. Commonly used in environmental education and law.
外来生物法は、生態系への影響を防ぐために作られました。
The Alien Species Act was created to prevent impacts on ecosystems.
外来種 (gairaishu) is the most common and general term. 移入種 (inyūshu) is more technical and emphasizes introduction by humans. 帰化種 (kikashu) specifically means a species that has become established and reproduces in the wild. In everyday conversation, 外来種 is usually sufficient.
The direct translation 「導入種」(dōnyūshu) is rarely used and may sound unnatural. Stick to the terms above.