European eel
Anguilla anguilla
Also known asAal (German) · Anguille (French) · Unagi (when culinary, though Japanese eel is technically A. japonica)
Water parameters
Minimum tank: 2000 L per individual at harvest size.
Feed and growth
- Feed protein
- 45% target
- Daily feed (warm)
- 1.50% of body weight
- Daily feed (cool)
- 0.50% of body weight
- Max density
- 80 g per litre
A 3000 g adult eats about 45.0 g of feed per day at optimum. 10 fish at adult size: ~450 g daily.
Legality
Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.
| Jurisdiction | Status | Notes |
|---|---|---|
| Worldwide | restricted | CITES Appendix II; EU export ban on glass eels since 2010 verified 2026-05-13 |
| European Union (bloc) | permit required | verified 2026-05-13 |
| United States (federal) | restricted | verified 2026-05-13 |
| New South Wales | prohibited | verified 2026-05-13 |
Unlisted jurisdictions default to "check local regulations".
Origin and habitat
Native to freshwater rivers, lakes, and coastal waters across Europe, from Scandinavia to the Mediterranean, and extending into North Africa. The species (Anguilla anguilla) has one of the most remarkable life cycles in the animal kingdom: adults migrate from European freshwater to the Sargasso Sea in the western Atlantic to spawn, and the larvae drift back on ocean currents over 1-3 years, arriving on European shores as transparent 'glass eels' that migrate upstream into rivers and lakes. Wild populations have declined by over 90% since the 1980s due to overfishing, habitat loss, pollution, and parasite infection. The species is listed as Critically Endangered by the IUCN. European eel aquaculture is significant (over 6,000 tonnes annually, primarily in the Netherlands, Denmark, Italy, and Spain) but relies entirely on wild-caught glass eels because the species has never been bred in captivity at commercial scale.
Climate and outdoor ponds
- Climate
- temperate (handles seasonal swings)
- USDA zones
- 6–11 (winter low around -23°C or warmer)
- Heating needed
- no
- Cooling needed
- no
Care notes
A high-value aquaculture species with serious sustainability and ethical considerations. European eel is a premium product commanding $15-40/kg depending on market and preparation. The eel is grown in recirculating aquaculture systems (RAS) at 22–28°C from glass eels (wild-caught juvenile stage) to market size (150–300 g) in 12-24 months. FCR is 1.5-2.0 on high-protein eel pellet (45-50% protein). Stocking density in RAS: 40-80 g/L. The critical issue is that every glass eel used in culture is taken from wild populations that are Critically Endangered. EU regulations restrict glass eel harvest and require that a portion of catch be used for restocking programs. Many conservation organizations argue that eel farming increases pressure on wild stocks rather than relieving it. For aquaponics, European eel is theoretically compatible (they produce waste that feeds plants efficiently) but the ethical and regulatory complexity makes it inappropriate for most operators. Glass eel supply is limited, expensive ($500-1500/kg of glass eels), and subject to international trade restrictions (CITES Appendix II). Not recommended for home aquaponics due to conservation concerns.