A thousands-years-old mystery has been solved

The European eel (Anguilla anguilla) has puzzled people for thousands of years. No one could find their eggs.
The Greek philosopher Aristotle thought that European eels might be sexless and regenerate spontaneously from mud. In central Europe, myths abounded about mysterious matings between snakes and fish.
It wasn’t until the 1920s that Johannes Schmidt was able to provide a realistic hypothesis. Through painstaking data-analysis of young eels collected in the Atlantic Ocean and the Mediterranean Sea, Schmidt narrowed down the potential spawning site to the Sargasso Sea. The Sargasso Sea is a region of the Atlantic Ocean, roughly northeast of central America, about 5,000 to 10,000km from the known habitats of the adults. The youngest European eel larvae have been found in this sea and nowhere else (by Schmidt and other scientists after him).

The idea grew that adult European eels migrate thousands of kilometres to spawn and hatch in the Sargasso Sea. It lacked direct evidence but remained the best one. In the last 10 to 15 years, satellite tags helped track adult European eels from several locations in Europe to the Azores islands.
Last October, new research showed that...