Prepare to be baffled by what we don't know about eels
6/5/202614 min
More than a century ago, all that people knew about European eels was that they lived in the rivers and streams for decades — until they swam out to the ocean and never returned. Eventually, tiny eels would show up and the cycle would start again. Where did the adult eels go? Where did the baby eels come from? Did they even reproduce at all or just spontaneously emerge into being? Science now has some — but not all — of the answers to these questions. Today on the show, Regina G. Barber talks to fish physiologist Arjan Palstra about this mystery and how close scientists are to solving it.
If you liked this episode, check out our episode on the Pacific lamprey.
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Regina Barber· Host0:15
[gentle music] You're listening to Short Wave from NPR. Hey, Short Wavers, Regina Barber here with a modern-day eel mystery. To this day, no one knows where they come from. Well, not entirely. [upbeat music] Centuries ago, people thought that baby eels just sprang up spontaneously from morning dew.
Arjan Palstra· Guest0:40
Or from mud or from slime, so, uh, they thought it was not like an animal that was reproducing, but just started to exist spontaneously from something.
Regina Barber· Host0:51
Arjan Palstra is a fish physiologist at Wageningen University and Research in the Netherlands. He says eventually people started looking for eel reproductive organs, like gonads, to convince the world that spontaneous generation wasn't happening.
Arjan Palstra· Guest1:07
Even a big name like Sigmund Freud, he started his career by looking for the gonads of eel, but, uh, never found them.
Regina Barber· Host1:15
[upbeat music] A couple decades later, somebody found an adult eel in the ocean, sex organs and all, and that part of the mystery was solved. But still, no one knew where they went to make baby eels. All they knew was that decades-old