European Eel

What you're looking at

The European eel (Anguilla anguilla) is one of the UK's most distinctive freshwater fish — and one of its most threatened. The species is critically endangered on the IUCN Red List; UK stocks have collapsed by over 95% since the 1980s. Always handle carefully and return unharmed.

Key features

• Body: Long, snake-like, cylindrical at the head and laterally compressed toward the tail. Continuous dorsal-tail-anal fin running around the rear half of the body.
• Skin: Smooth, leathery, heavily slime-coated. Scales are tiny and embedded — appears scaleless.
• Colour: Yellow-brown back fading to creamy belly ("yellow eel" stage). Mature migrating fish ("silver eels") turn dark on top and brilliant silver below with enlarged eyes.
• Mouth: Lower jaw projects slightly beyond the upper, with small backward-pointing teeth.
• Size: Most caught fish 0.2–1 kg; large yellow eels 1.5 kg+; mature silver eels can exceed 3 kg.

Confusion species

• Lamprey: No paired fins, sucker-disc mouth (no jaws), gill openings as a row of round holes — not a fish in the same family at all.
• Conger eel: Marine species, much larger, dorsal fin begins much further forward (level with the pectoral fin). Rare in fresh water but possible in tidal estuaries.

Handling and release

Eels are remarkable escape artists and very slippery — work them on a wet unhooking mat with the hands wetted. Single barbless hooks are kindest; deep-hooked eels should have the hooklink cut and the hook left in place (the acidic stomach dissolves it within days). Do not keep eels. Even though it's legal to catch them recreationally on a rod licence in England and Wales, the population is collapsing and every fish counts. Note the catch on this app, photograph it on the mat, slip it back.