European Eel

Fascinating facts about the European Eel

• A European eel spends 5 to 20 years in rivers and lakes eating smaller fish, then one autumn night its eyes swell, its sides turn silver, and it stops eating entirely. What triggers this? The Moon's phase and water temperature. The eel then swims 5,000 miles across the Atlantic to the Sargasso Sea — a patch of ocean between Bermuda and Africa — to spawn once and die. No one has ever watched this happen.
• The eel's journey across the Atlantic is powered by a body that is 60% muscle and fueled by fat reserves built up over decades, yet the fish doesn't eat a single meal during the entire 6-month crossing. It navigates by sensing Earth's magnetic field, following ocean currents, and reading the stars — a navigation system so precise that eels born in different European rivers arrive at almost identical spawning grounds thousands of miles away.
• Glass eels — transparent hatchlings the width of a spaghetti strand — drift on ocean currents for 300 days after hatching in the Sargasso Sea, then transform into elvers and invade European rivers by the millions. In the 1980s, recruitment crashed: today fewer than 5% of the eels that arrived 40 years ago now make the journey, a collapse so severe the species is listed as Critically Endangered despite being legally protected across Europe.
• An eel can breathe through its skin as well as its gills, allowing it to survive for hours out of water — a skill that lets it wriggle across wet grass and muddy banks to reach isolated ponds and lakes that other fish cannot reach. This adaptation also lets it hide in river mud during droughts, waiting years for water to return.
• The eel's entire life cycle remained a mystery until the 1920s when Danish scientist Johannes Schmidt followed glass eels back across the Atlantic and proved they came from the Sargasso Sea — solving a 2,000-year-old riddle that had baffled everyone from Aristotle to Darwin. Even now, no scientist has filmed a wild eel spawning or explained how babies born in the open ocean know which European river to invade.

At a glance

About the European Eel

In the mysterious depths of European waters, a serpent-like creature navigates the darkness with an ethereal elegance, its slender body undulating as it propels itself through the currents with a mesmerizing fluidity. The European Eel, a master of stealth and endurance, embarks on an extraordinary journey, migrating thousands of miles across the continent to reach its breeding grounds, a testament to its unyielding determination to survive. As it glides effortlessly through the shadows, its very existence is a poignant reminder of the delicate balance of the natural world, and the urgent need to protect this enigmatic creature from the brink of extinction.

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