Why We Haven’t Learned More In 101 Years Of Trying

Almost everything we know about the reproductive practices of European eels comes from a genius study conducted more than 100 years ago.

LEARN MORE
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To learn more about this topic, start your googling with these keywords:
- European Eel: A long-lived, snakelike fish native to the rivers of Europe.
- Eel, Pie, and Mash: A common meal of poorer Englishmen for the last several centuries.
- Spontaneous Generation: The hypothetical process by which organisms would generate from non-living matter.
- The Eel Question: A matter of great debate for millenia - specifically: how do eels reproduce and where do they come from?
- Sargasso Sea: A region of the Atlantic Ocean off the coast of Bermuda bounded by four currents forming an ocean gyre that is recognizable by the large presence of Sargassum seaweed.

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CREDITS
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David Goldenberg | Script Writer, Narrator and Director
Lizah van der Aart | Illustration, Video Editing and Animation
Nathaniel Schroeder | Music

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REFERENCES
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[petersmythe]

"We are still yet to find a single wild eel egg"
That's a pretty impressive lack of results.

[thewilltheway]

I feel like the importance of direct evidence to the scientific community was understated. Also understated was how this relationship of modern science being able to experimentally confirm predictions made decades earlier is very frequent. For examples, 2017 nobel prize in physics was awarded for the "discovery" of gravity waves, but Einstein had predicted their existence and their basic behavior in 1916 based on available experimental evidence. Yet the work of these modern scientists is important and worthy of our praise. Direct evidence is not only necessary to confirm the hypothesis, but gives us additional nuance that is essential for making further predictions.

[singerofsongs]

Freud being obsessed with eel gonads is the most Freudian thing I’ve ever heard

[WooliteMammoth]

Very cool! Will eels not breed in captivity at all? Has anyone tried to increase the salinity of their water over time to simulate a migration to salt water?

[StefanLopuszanski]

I've spent time researching this and the rabbit hole is fascinating. The fact we simply don't know some seemingly basic things we all assumed we know is mind-boggling.

Surprised you didn't mention about the attempts to breed in captivity and how much it has failed.

[enricohepner]

(an old quote by Sam O'Nella questioning the need to receive eel genitalia)

[lillithcollins]

I did field research on American eels as an assistant a few years ago. They were honestly such interesting and clever creatures. I had a meter long one wrap itself around my arm and then sneak its tail onto my shoulder, only to suddenly use its tail on my should like a springboard and rocket out behind me into the water. Not the first last I was tricked by an eel.

[SearchOfSelf]

It's incredible that people used to eat eels everyday at one point! This highlights how important it is to be mindful and avoid overfishing or damaging the natural environment 🎣

[sadhar]

Aristotle sure had strange ideas about so many things.

[technetium]

You know what, for someone not to know the existence of the Americas, and the fact that eels die after giving birth and their babies come out fully formed when they reach Europe, Aristotle got a pretty reasonable conclusion

[smileypirate]

Correct me if I'm wrong, but if I remember correctly, previously the different life stages of eels were thought of as different species and that's why no one found any small eels. Eels mainly arrive along the European coast as glass eels, not as fully developed eels. Glass eels looks quite different to adult eels, and therefore were thought of as a different species.

After glass, it becomes yellow eel and when sexually mature it turns to silver and begins it's journey back to the sargasso.

[WilsonWAW]

This got my attention, I was quite intrigued with this topic. Thank you for covering this subject.

[tiffanysandmeier]

I feel like this is an oversimplification of what was discovered. Yes, they knew that the saragasso sea was the breeding grounds, but didn't know how the eels got there. Also talking the size of eels seems to dismiss the fact that eels at different stages of their life cycle look considerably different. As in there are different names for the different stages. Sometimes so different that it wasn’t known that they were the same species until fairly recently.

[BizarreBeasts]

What a fantastic way to explain how that early research was done!

[Bayoll]

Ahhh, Sigmund Freud and eels...
Bring backs some memories

[alfonsoballesteros]

I think that I need to share my knowledge about what I know from the baby eels and I didn't found on the video. First of all I have to say that I am from Spain and in my country we have a long tradition will eels and most important with BABY eels (called "angulas" in Spain). I think that maybe this is the only part in the world that this happens, but it will be great if someone else could share if their culture have this food too. In the northern part of the country, on the Cantabrian sea, for many years it was so common for the fishermen to find gooey balls of baby eels very close to the dock. At that time the product was very cheap because it was like the rubbish from the sea. But then it came the japanese people and their love for adult eels and their need for them to keep rice fields free of insects, so they started to buy all the bay eels to grown them in adults (I never knew if it was true or just a lie for raising the price), but because of the increasing demand of the japanese people and also the small amount of baby eels that you can find, the price on the market for this product got crazy, to the point that it is the second most expensive fish product that you can find (after caviar). Because of this and the fact that spanish people were used to this product, a man find an amazing idea for recycle bad fish and to keep the tradition of eating this baby eels. He decided to take the fish that can't be sold (because of their size their aspect or any other reason) and make like a minced meat, then cook it and cut it on the same size and form of the baby eels. The product called "gulas" now it can be found on every supermarket on Spain, it is cheap, healthy and tasty, and the true "angulas" can still be purchased on the market at prices around 1000-1500€/kg only for those who can pay for them or for very special events. They are not amazing on taste and surprisingly very similar to the fake ones.

[TojiFushigoroWasTaken]

Its insane how they figured it human ingenuity, must feel so satisfying when they eventually figured it out

[andrycraft]

Nice to hear that the Red Skull was also a renowned biologist interested in eels.

[rodneynormanhersom]

i found baby knot eels on the wall of a drain in Hervey Bay Qld Australia they were clear and around 2 to 3 inches long and they could climb as they climbed out of the cooler we put them in

[storyspren]

Do we know if the eel gonads that develop are always the same for the any single eel, or are they more like Gethenians, sometimes developing male and other times female? Or is that one of the many things we don't yet know?