Spare a thought for the humble European eel. These ancient fish begin as eggs somewhere in the western Atlantic Ocean’s Sargasso Sea—the exact location of the spawning grounds of Anguilla anguilla remains a mystery. As larvae, they drift toward Europe, more than 3,000 miles away. Along the journey, which can last for two years, they develop into glass eels, as shown in the photo above: near-translucent creatures, a few inches long at most. “As a glass eel, you’re a tiny animal, you’re one-third of a gram,” says biologist Willem Dekker,…
