The eel, who was known as Ale (confusing), lived in the southern town of Brantevik and was owned by Tomas Kjellman, who moved into the cottage next to the well with his family in 1962. Kjellman told Swedish paper The Local that "we always knew the housepet was included."
Guests had come to Kjellman's home for a crayfish party on Friday. Expecting to entertain his guests with a little "oldest eel ever!!" showing, he opened the well for all to see.
But when they removed the lid from the well, they saw that the world's oldest eel had kicked the proverbial bucket.
"It was uncanny when we took off the lid and saw it in pieces. It had apparently been there for a while and had basically boiled."
The eel received no burial, but is in a freezer awaiting expert analysis - which may solve the riddle of how the sea creature got so incredibly old.
Rest in peace, Ale the old eel. You lived to 155, which is 148 years longer than most eels are expected to live.
[Image via The Local]