Sattler told the Chicago Tribune that Granddad had been losing interest in his food over the past couple of weeks and exhibiting signs of a "shutting down" of vital systems on Saturday.
Granddad, according to Shedd's blog, "was the last standing (or swimming) among Chicago's beloved trio of ancient animals, which also included a dwarf African crocodile, R1, who lived at Lincoln Park Zoo from 1930 to 2010, and Brookfield Zoo's 83-year-old Major Mitchell's cockatoo, Cookie, who died in August of last year". Lungfish have remained virtually unchanged for over 100 million years. "During his almost two-year hiatus in a reserve area, staff members repeatedly assured anxious aquarium members and other guests that their favorite lungfish was doing fine and would be back on view in a spacious new habitat recreating a Queensland riverbank ecosystem".
"Granddad delighted guests when several times an hour he would slowly rise from his apparent torpor at the bottom of the habitat, slowly flap his large pectoral and pelvic fins, and slurp air at the surface". Through the decades, Granddad has charmed and amused roughly 104 million visitors, according to Shedd Aquarium. To mark the occasion, he received a unique layered cake filled with a few of his favorite ingredients, including smelt, shrimp, yellow squash, carrots, potatoes and green peas. "I remember seeing him when I was a little boy visiting the aquarium", he wrote.
Body of missing filmmaker found
He took the deepest dive, resurfaced and gave an Ok signal to the crew, but his partner began to lose consciousnesses. While the crew tended to him, Stewart disappeared into the water.
Ever since the lungfish was placed in its new enclosure, it managed to steal the hearts of its caretakers and tourist who would, more than often, swing by to see Granddad's gimmicks. "He seemed as permanent a fixture at Shedd as the terra cotta fishes that decorate the building inside and out", the Shedd said in an online obituary Monday.
Granddad appears to have been a firm favorite for numerous aquarium's visitors.
Age is a bit of a theme with lungfish.