Eel at Home

One thousand leagues into the sea: a marine biologist’s quest for the birthplace of the freshwater eel.

Eel at Home

The first time I saw an eel was at an aquarium. Despite having just seen an extensive variety of fish and other sea creatures, it still took me by surprise. The eels were a perfect mystery; looking like the snakes I had seen near my house, but with fins like fish!

I remember being scared of these black, wriggly creatures — hesitant to get closer, yet curious to learn about them.

It was years later, probably in middle school, that I came across eels again. I learnt about their amazing ability to generate electric charges, their flexible backbone, and other cool facts. Once again, I marvelled at the nature of this creature. How does something so beautiful and extraordinary exist on this planet along with us? Yet again, I didn’t pursue my curiosity–it got buried with all the other interests I’ve had over the years, but never pursued.

I’m sure we have all had such thirsts for knowledge that we’ve forgotten about, but what about those who did manage to chase after their curiosities?

When defining curiosity, I like to turn to Mario Livio. He’s an astrophysicist and also the author of Why? What Makes Us Curious, and he sums up the answer perfectly: “It’s a bit like an itch that we need to scratch.”

Why do we feel curious? What is it that makes us so driven to find the answer to a random question?

Have human beings always been curious? Some quick internet searches may provide you with the same answers that I sought after; curiosity has been around for a long while. After all, why would we create something as irrelevant as a flute back in 900 B.C. or even earlier? Those humans seemed to have some motivation within themselves to create an instrument that could produce beautiful sounds — something that didn’t benefit their survival at all.

It’s not empty words after all when they say “curiosity killed the cat, but satisfaction brought it back”!

It seems, important knowledge relevant to one’s endurance, social standing, and so on, is not our only motivation to seek out answers.

There seem to be internal factors at play. After all, discoveries weren’t made only for the sake of survival, they were also made because of frustratingly unanswerable questions too. How else would we know why the sky is blue, or why we don’t seem to fall off earth despite being “upside-down”?

Epistemic curiosity, which is the drive to fill up information gaps in your brain, is most often associated with science, and the urge to find and discover, and so is the closest term to what we mean when we talk about curiosity.

Of course, while epistemic curiosity may be a bit pointless to start with, its results can eventually end up being useful. When the great scientist Galileo Galilei was 20, he was observing a lamp swinging from a cathedral ceiling, just for fun. He ended up inventing the pendulum — thereby setting the foundations of modern-day timekeeping. More obscurely, the mathematician G. H. Hardy was very proud of the fact that his study of complicated prime-number algorithms had no use in the real world. But he couldn’t have known that today, we use them every day for encryption and cryptography.

And so, one can say, scientists are often people fuelled by curiosity.

Johannes Schmidt, a Danish scientist, was one such human being.

Like me, he too was curious about eels, though of course, his interest was a lot greater than mine. He was especially interested in finding out about the early life history of the European (Anguilla Anguilla) and American freshwater eels (A. rostrata). Schmidt was a marine biologist, working part-time for the ‘Danish Commission for Investigation of the Sea’ from 1902–1909.

Since this was the dawn of the 20th century, scientists were aware that eels were breeding similar to other fish, but they had no idea where they bred. And so, in 1904, Johannes Schmidt decided to lead a series of expeditions into the Mediterranean Sea and the North Atlantic.

Little did he know how long his quest would last.

There are more than 800 species of these slender, elongated fish that belong to the order, Anguilliformes. They are usually scaleless, with long dorsal and anal fins that are continuous around the tail tip. They are found in all seas — from coastal regions to mid-depths. While they primarily live in saltwater, some of them travel between salt and freshwater environments to breed–growing to maturity in fresh water and then returning to the sea (a journey that can take 2 to 3 years) where they spawn and die.

So, what are these creatures?

Well, you know them best as eels. And no, these aren’t the funky electric ones that you’ve probably read somewhere about, these are called true eels.

(In fact, the ones we call electric eels, aren’t even eels! Despite its name, they are actually knifefish–a member of the order Gymnotiforms, and are more related to carp and catfish than eels.)

While electric eels can grow to about 2.75 m long, mature true eels range from 10 cm to 4 m long; the longest one ever caught being a slender giant moray eel which was 3.9 m long, about the height of an elephant! And when electric eels use electric currents to hurt a predator/prey, true eels use their strong jaws and their small, sharp teeth to defend themselves. Luckily for us, true eels are mostly nocturnal and tend to stay hidden in the sand, or under rocks.

John Schmidt set sail on the shores of Europe looking for and catching eel larvae. The process was a rather interesting one: he would take them in for inspection, measure their length, and then release them back into the ocean. The idea was that if he measured different sizes from all over the waters, the place which had the smallest larva that he found, would be the birthplace of eels.

While he was sailing the Atlantic in search of eels, the rest of the world was going through its own changes. The world’s first vehicle license plate was issued, in the Kingdom of Prussia, and the Wright Brothers became the first humans to fly a plane. Einstein submitted his seminal paper; the Sinn Fein party was founded to fight for Irish independence; Henry Ford released the Model T automobile.

By this time, John Schmidt had realised that eels near the European coastline were rather big, so he went out further into the ocean: into the Atlantic and towards the Americas. He realised that the further west he went the smaller they got, so he was certainly on a trail!

Elsewhere, life carried on. Gandhi launched his nonviolent movement in South Africa; slavery was abolished in China; the Oreo cookie was invented; someone stole the Mona Lisa because he thought it should belong to Italy but was eventually arrested. The Panama Canal was built, linking the Pacific and the Atlantic. World War One broke out, sucking many countries in and making the Atlantic a dangerous place to sail. John Schmidt, however, carried on with only one purpose in mind: the birthplace of the eel.

The war eventually died down, giving way to the Russian Revolution, when Schmidt finally reached his destination. The world was certainly a different place by then: he had been sailing for over eighteen years!

What John Schmidt found, though, was certainly worth the wait. Tucked away, in the corner of the Atlantic, in the windless calms of the Sargasso Sea, were the baby eels.

The name Sargasso itself is derived from the Spanish word “sargazzo” which means seaweed/kelp, and it may help us understand why there are so many myths and legends surrounding the sea. Cristopher Columbus back in the 1400s is credited with the first written account of the sea, in which he mentions that the sailors saw the seaweed as a sign of shallow waters, and were scared that the ship would get entangled in it, run aground and eventually drag them down to the ocean floor.

The eels were born and bred in the Sargasso Sea, before they used ocean currents to disperse to their respective freshwater habitats in Europe and North America.

Doesn’t this tell us something about our curiosity and how driven we are to find answers?

No external factors were making and tempting Johannes Schmidt to sail around the Atlantic looking for the birthplace of eels; no prestige, no money, just plain curiosity.

And just like the phrase “curiosity killed the cat but satisfaction brought it back”, wouldn’t it be nice if we could just do what we are curious about? Because that’s what this Danish scientist did, and even though parts of his work have been disputed, much of it is still relevant and largely accepted.

What would you do if you could be driven by your curiosity alone? If you’re like me, you might spend a whole day googling random trivia, or you might even want to spend your entire life travelling around the world. And, what would the people around you do? What would the world around us look like? Quite different, I’m willing to bet.