Eels so common they are used as currency

1086 CEEngland

“Eels were once so common as to be a form of currency: the Domesday Book lists hundreds of water mills whose rent was paid in eels, or “sticks” of 25: 2,000 eels to “Giles brother of Ansculf” in Datchet, Bucks; 1,000 sticks from Bottisham in Cambridgeshire.”

John Henley, "The decline of the eel," The Guardian, October 27, 2010, https://www.theguardian.com/environment/2010/oct/27/the-decline-of-the-eel.

Image: George Arents Collection, The New York Public Library. “Broad-nosed or yellow eels.” The New York Public Library Digital Collections.