Endangered
Japanese eel
Anguilla japonica
Japanese eel is a ray-finned fish in the family Anguillidae (order Anguilliformes) — Anguilla japonica, recorded as Endangered.
Range and habitat
The Japanese eel and other anguillid eels live in freshwater and estuaries, an area where a freshwater river meets the ocean. The adults of the Japanese eel appear to spawn in the upper few hundred meters of the ocean, based on the recent catches of their spawning adults, eggs, and newly hatched larvae. After hatching in the ocean, the leptocephali are carried westward by the North Equatorial Current and then northward by the Kuroshio Current to East Asia. Before they metamorphose into the glass eel stage.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
In the open ocean, leptocephalus, the first stage after the egg, feed on marine snow. The migration time of this species corresponds with the moon as it affects the tide.
This time is during a tide that occurs at night and simulates a flood making it easier for the eels to survive their migration. This migration is generally nocturnal, and the eels face few predators.
In crisis
Even so, presumably due to a combination of overfishing and habitat loss or changing water conditions in the ocean interfering with spawning and the transport of their leptocephali this species is endangered. In Japan, research has been conducted on the full life-cycle aquaculture of the Japanese eel as a means of addressing the underlying problem of declining wild populations. In 2026, kabayaki prepared from fully farmed Japanese eel was commercially introduced for the first time.
This species relies on this environmental signal to know when to migrate in and out of their fresh water habitat. Thus, the change in water temperature is directly proportional to the decline in population size.
Japanese eel is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Japanese eel, Wikidata item Q1140081. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
