Japanese Eel (Anguilla japonica) — identification, habitat & look-alikes

Japanese eel is a long-bodied fish that grows in East Asian rivers and coastal waters, then travels far offshore to spawn west of the Mariana Islands. No established U.S. population has been confirmed, so an eel in an eastern U.S. river is much more likely to be an American eel (Anguilla rostrata).

Appearance

Appearance: It has a long, smooth-looking body, a dark back, and a pale belly. Its tiny scales sit beneath the skin.

Look-alikes

American eelAnguilla rostrata

A wild eel in an Atlantic or Gulf Coast river of the United States is ordinarily an American eel. The two species look alike, so a photograph alone is not a secure way to identify a Japanese eel there.

Why they get mixed upBoth are long freshwater eels with dark backs.

Where it lives

Typical habitats: East Asian rivers
estuaries and coasts
Range: Its native range includes Japan, Korea, China, Taiwan, and nearby waters. Introductions for aquaculture have occurred outside that range, but no established U.S. population has been confirmed.
Migration: Adults leave rivers and coastal waters for spawning waters west of the Mariana Islands.

Behavior

Diet: In its East Asian range, it feeds on crustaceans, insects, and fish.
Activity: It is most active at night.

Life cycle

Reproduction: Leaf-shaped young drift on ocean currents toward East Asia and become clear, slender before entering rivers.

Conservation

IUCN Red List: ENEndangeredVery high risk of extinction in the wild

Culture and stories

Culture and stories: This eel is harvested and raised for food in East Asia.

11 sources