90-year-old Aussie lungfish euthanised in Chicago after record innings

A 90-year-old Australian lungfish acquired by a Chicago aquarium in 1933 has been euthanised after becoming the longest-living fish in a zoological setting.

The fish, known as Granddad, was euthanised because of failing health, officials from the Shedd Aquarium announced.

The aquarium said the fish was "humanely euthanized Sunday due to a rapid decline in quality of life associated with old age." Source: Shedd Aquarium

Granddad came to Shedd from Australia in anticipation of the 1933-34 Chicago World's Fair and was seen by more than 104 million people during his time in Chicago, aquarium president Bridget Coughlin said.

"For a fish who spent much of his time imitating a fallen log, he sparked curiosity, excitement and wonder among guests of all ages who would hear his story and learn about the incredible biology that makes his species a living fossil and one of the oldest living vertebrate genera on the planet," Coughlin said.

Shedd Aquarium is paying tribute to the fish who arrived at the aquarium in 1933. Source: @shedd_aquarium/Twitter

According to the aquarium, lungfish, which can live to be more than 100 years old and are a protected species in Australia, have existed for nearly 400 million years and fossils show they have remained unchanged for over 100 million years.

Lungfish, which are native to the Mary and Burnett rivers in Queensland, Australia, have a single primitive lung and are among the few fish that can breathe air.

A Shedd spokeswoman said Granddad's exact age was unknown but that he was believed to be in his mid-90s.

The aquarium said Granddad was euthanized after losing interest in food and showing signs of organ failure.

"When a physical examination showed that the geriatric fish’s organs were failing and his quality of life was slipping away, our Animal Health team made the humane decision to euthanize him," Karen Furnweger wrote on the aquarium's website.

The world-famous Australian lungfish experienced a rapid decline in health. Source: Shedd Aquarium

Granddad was at the facility for nearly 84 years and certainly made an impression on those who visited him during that time.

Hundreds have paid tribute online.

Nathan de Rover wrote on Facebook: "Granddad meant a lot to me. I remember seeing him when I was a little boy visiting the aquarium."

"In fact, in 2015, my wife and I got married at the aquarium right in front of his tank so he could be our witness."

Jenni Doughty said: "We always make sure to visit him first, before anything else everytime we visit.

"My kids liked to look at him and guess what he was thinking, and what he would say back to them!"

The aquarium has even said an Australian writer spent a day visiting the lungfish as his story was inspiration for an upcoming novel.

Today's top news stories - February 7