I didn’t know there was a fish in the world whose life still remains such an unknown. Unlike most fish, freshwater eels spawn in the wide open ocean, and the tiny larvae travel to rivers where they swim up against current (as small glass eels) then spend forty years or more living there. As mature adults they swim back to the ocean. No-one knows how they find their way back; it’s supposed they spawn in the Sargasso sea. Sometimes eels get trapped in lakes or behind dams with no way out, and there are tales of them living close to a century, searching every year for a way back to the sea. To date nobody has ever found the actual spawning site. But fishing pressure urges some scientists to search: they think they could learn something that would help breed eels in fish farms to produce for market. Others say it should never be found (what good would it do the eels, if we caught them in the act?) It shows the completely different ways eels are viewed: as a food item to be exploited, as something slimy and icky no-one cares about. Or, as the author found when he traveled to Micronesia and New Zealand, an ancient and powerful creature to be feared and respected. In those island cultures eels are woven into tales of power and mystery, and many people cared for and fed eels that lived in streams near their houses, for decades. This part of the book felt more like a travelogue, a story of stories told and people visited and as such not quite as interesting to me. Mostly I got an impression of how difficult it was for the author to gain the trust of the locals and ferret out their legends and information about eels. He also tells of visiting several eel fishermen, in particular a man who every year builds a rock weir on a river to catch eels during the run to the sea. Overall the book felt a bit disjointed, I wanted to be more interested in it but kept having to turn myself back to it. I wished for a lot more material, in depth. And I felt like it could have been had: the afterward mentioned a lot more visits and conversations that didn’t get mentioned in the text as far as I could tell.