There was a book about the eels being born from Sargasso sea, all transparent at first, that I remember reading ages ago. It mentioned a lot of legends as well surrounding the eels, because the young ones were never seen - only fully grown eels.

I cannot remember precisely, but to explain their existence, there were even some recipes about "creating" eels. I think one was something similar to "put a couple of sticks under a bit of wet turf for a night". And that is how the witches were able to create the eels.

I wish I could remember the title of the book, but unfortunately it was more than 30 years ago when I read it.

"The Book of Eels" touched a lot of topics you mentioned, not sure about the witch bit though. It was published in 2020 so probably not the one you are looking for. https://www.goodreads.com/book/show/51938590-the-book-of-eel...

Was it Waterland by Graham Swift (fiction, but has some eel diversions IIRC)?

> because the young ones were never seen - only fully grown eels.

Only, as it turns out, per the article the ones you normally see are _not_ fully grown eels; the sexually mature stage is also rarely seen.

my favorite online newspaper recently did a long form piece on eels and their decline in Italy ([1] - Italian only, sorry).

The comments mention a couple of books:

- Brian M. Fagan, Fish on Friday

- Patrik Svensson, The Gospel of the Eels (also wrote another book on eels)

maybe it's one of these two!

[1]: https://www.ilpost.it/2025/05/29/anguille-comacchio/