Credit: Gordon Hides (used with permission)
On Sunday, February 5, 2017, Granddad the Australian Lungfish, the oldest fish in any aquarium or zoo, was euthanized due to health complications. Although his exact age is unknown, he arrived at Shedd Aquarium in Chicago as an adult in 1933. Australian Lungfish (Neoceratodus forsteri) take over a decade to mature, so we can estimate he was over 90 years old when he passed.
The Australian Lungfish is a unique species, considered a “living fossil”, resembling its ancestors whose lineage dates back over 380 million years. The Australian Lungfish genus (Neoceratodus) itself has been around for about 100 million years. When first described, they were believed to be amphibians; one look at their elongate body and flipper-like fins, and you can imagine the classification conundrum. The fish even possesses a primitive lung, allowing it to breathe air in low-oxygen environments (although they usually breathe with their gills).