# European Eel (*Anguilla anguilla (European eel)*)

> The European eel is a long, snake-like fish that migrates thousands of kilometres between European rivers and the Sargasso Sea in the western Atlantic, where it spawns and then dies. Adults reach about 1 m in length, weigh up to around 2.5 kg, and can live 20 years or more in fresh water before making their final journey. Once abundant, the species is now Critically Endangered, with young eel arrivals down by more than 95 percent.

- **Category:** Fish
- **Conservation status (IUCN):** Critically Endangered
- **Range:** European eels live in rivers and coasts of Europe; American eels in eastern North America; both migrate to the Sargasso Sea in the western Atlantic to breed.
- **Canonical page:** https://globalanimalguide.org/animals/european-eel/
- **Last reviewed:** 2026-07-16

## Scientific classification

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Actinopterygii
- **Order:** Anguilliformes
- **Family:** Anguillidae
- **Genus:** Anguilla

## Facts at a glance

| Attribute | Value |
| --- | --- |
| Scientific name | Anguilla anguilla (European eel) |
| Diet | Carnivore (fish, worms, crustaceans) |
| Habitat | Rivers, estuaries, and the open Atlantic Ocean |
| Lifespan | Up to 20+ years in rivers; dies after spawning |
| Migration distance | 5,000–10,000 km to spawning grounds |
| Conservation status | Critically Endangered (IUCN) — arrivals down 95%+ |
| Spawning site | The Sargasso Sea, western Atlantic |

## A fish built for two worlds

The European eel spends most of its life in fresh water yet breeds far out in the open ocean, so its body must cope with both. It has a slender, muscular, snake-like form covered in a thick layer of slime, which helps it swim through water and even wriggle short distances across wet ground. A continuous fin runs along its back, tail and belly, giving the smooth, undulating stroke it uses to swim upstream. Adults typically grow to about 1 m long and can weigh up to roughly 2.5 kg.

## The Sargasso Sea mystery

For centuries no one could find where eels bred, a puzzle that occupied naturalists from Aristotle onward. It is now known that European eels swim 5,000 to 10,000 km across the Atlantic to spawn in the Sargasso Sea, then die. Their leaf-shaped larvae drift back toward Europe on ocean currents over a journey that can take years. Remarkably, no adult has ever been directly observed spawning in the wild, so parts of the cycle remain a mystery.

## Metamorphosis and life cycle

The European eel passes through several dramatic body forms during its life. Larvae hatched in the Sargasso Sea transform into transparent 'glass eels' as they reach coastal waters, then darken into young 'elvers' that push up rivers. They spend most of their lives as 'yellow eels', feeding and growing in fresh water for a decade or more. Finally they become silvery 'silver eels', their eyes enlarge and their guts shrink, and they set off on the one-way migration back to the sea to breed.

## Diet and feeding

The European eel is a carnivore and mostly a nocturnal hunter. It feeds on fish, worms, crustaceans, insect larvae and other small prey it finds along river and estuary bottoms. Its keen sense of smell helps it locate food in murky water and after dark. Once eels enter their final silver-eel stage and begin the migration to spawn, they stop feeding altogether.

## Why it is Critically Endangered

The European eel is listed as Critically Endangered by the IUCN, and the number of young eels arriving in European rivers has collapsed by more than 95 percent since the 1980s. Dams and weirs block their migration routes, while habitat loss, pollution, parasites and changing ocean currents all add pressure. Overfishing, including illegal trade in glass eels, has compounded the decline. Because so much of the eel's life cycle happens out of sight, protecting it is unusually difficult.

## Eels and people

The European eel has been fished and eaten across Europe for thousands of years and features strongly in the food culture of countries around the North Sea and Mediterranean. Traditional dishes such as jellied eels were once common fare, and smoked eel remains a delicacy. Today, concern over the species' collapse has led to fishing restrictions and trade controls. Conservation projects now trap young eels and move them past river barriers to help them reach suitable habitat.

## Frequently asked questions

### Where do European eels breed?

European eels breed in the Sargasso Sea in the western Atlantic Ocean. Adults swim between 5,000 and 10,000 km from European rivers to spawn there, and they die afterward.

### How long do European eels live?

European eels can live for 20 years or more in rivers before beginning their final migration. They die after spawning at the end of that journey.

### Why is the European eel endangered?

It is listed as Critically Endangered because arrivals of young eels have fallen by more than 95 percent. Dams blocking migration, habitat loss, pollution, parasites and overfishing have all driven the decline.

### What do European eels eat?

European eels are carnivores that hunt mainly at night, eating fish, worms, crustaceans and insect larvae. They stop feeding entirely once they begin their migration to the sea to spawn.

### How big do European eels get?

Adult European eels typically reach about 1 m in length and can weigh up to roughly 2.5 kg. Females tend to grow larger than males.

### What is a glass eel?

A glass eel is a young, transparent stage of the European eel that reaches coastal waters after drifting from the Sargasso Sea. They then darken into elvers as they move up rivers.

---
Source: Global Animal Guide (https://globalanimalguide.org/animals/european-eel/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.