Fisheries experts in Sweden plan to examine the head of Ale the eel to try to determine whether it did indeed live to the ripe old age of 155. Ale died last week in its home — a well on the property of Tomas Kjellman in the fishing town of Brantevik in southern Sweden. According to Swedish news website The Local, the eel was the world’s oldest and its life in the well was “well-documented” for more than a century. "Of course it's sad. I have memories of the eel from when I was a child," Kjellman told The Local.
Swedish fisheries expert Håkan Wickström of the Swedish University of Agricultural Science’s Institute of Freshwater Research will examine the otoliths, the bone-like calcium carbonate particles in the eel’s head, to try to verify the creature's true age. Similar to the growth rings on a tree, otolith rings can reveal the estimated age and growth rate of fish. “Hopefully the head is still whole and intact so the otoliths (earstones) are still there and in good shape,” Wickstrom told NBC News by email. “They have to be ground and polished and then analyzed in a microscope.”
Fellow fish expert Johan Wagnström said it wouldn’t be surprising if it turns out Ale lived as long as the press reports suggest. “I'm sure that it is a very old eel and I think it is possible that it was 155 years when it died,” Wagnström told NBC News. “According to the scientists, it is not an impossible age, although it is an extremely old age. A cold well have the specific conditions that the eel requires for a long life." Ale was a European eel, Anguilla anguilla. The average life expectancy for the species is usually 10 to 20 years, though one specimen named Pute lived in an aquarium for 85 years, aquatic scientist and eel expert William O’Connor told NBC News.
— James Eng