European eel
A critically endangered eel with a mysterious life cycle.
The European eel (Anguilla anguilla) is a species of eel whose life history was a mystery for thousands of years, with mating in the wild never observed. It is critically endangered due to hydroelectric dams, overfishing, and parasites.
- Scientific name
- Anguilla anguilla
- Conservation status
- Critically endangered
- Maximum length
- 1.33 metres (4 ft 4 in)
- Spawning ground
- Sargasso Sea
Lore & Background
European eels undergo five developmental stages: larva (leptocephalus), glass eel, elver, yellow eel, and silver eel. These stages were originally thought to be different species. Adults in the yellow phase are typically 45–65 cm long, rarely exceeding 1.0 m, but can reach 1.33 m. After spawning in the Sargasso Sea, larvae drift toward Europe over 300 days. They metamorphose into glass eels, enter estuaries, and become elvers. As they grow, they become yellow eels, then silver eels that migrate back to the Sargasso Sea to spawn and die. Feeding occurs mainly at night via scent, on worms, fish, mollusks, crustaceans, and occasionally plankton. They are preyed upon by larger eels, herons, cormorants, pike, and seagulls (on elvers).
Reader's Guide
The European eel is critically endangered, with numbers reaching Europe declining by around 90% (possibly 98%) since the 1970s. Contributing factors include overfishing, parasites such as Anguillicola crassus, hydroelectric dams, and natural changes in ocean currents. PCB pollution may also be a factor. The TRAFFIC program and CITES Appendix II listing aim to control trade. Hydroelectric dams have caused nearly twice the reduction in eel numbers over 80 years compared to dam-free waters. Eels have been important as food, with glass-eel fishing economically significant in Europe. The United States imports 11 million pounds of eel annually for sushi. Breeding projects have sought to rear eels in captivity. The PRO-EEL project, involving multiple European and Tunisian institutes, continues research.
Did You Know?
- Mating in the wild has never been observed.
- The five developmental stages were originally thought to be different species.
- Larvae feed on various planktonic organisms, especially microscopic jellyfish.
Frequently Asked Questions
Who is European eel?
European eel is the catadromous bony fish species Anguilla anguilla, a slender, sinuous creature that spends most of its adult life in European freshwater rivers and lakes before making a dramatic oceanic journey to reproduce. It is currently listed as critically endangered, making it one of the most threatened fish species on the planet.
How does European eel's story end?
After completing its long oceanic migration to the Sargasso Sea, the eel releases its eggs and dies, a terminal spawning event that has never been directly witnessed by scientists in the wild. This once-in-a-lifetime reproductive act closes the chapter on a 15-to-20-year life spent in European waters.
Why is European eel important?
European eel acts as a keystone predator linking riverine and oceanic food webs across its vast migratory range. Its critically endangered status—driven by hydroelectric dams, overfishing, and parasitic infections—makes it a flagship species for conservation policy across the European Union.
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