Pandora, the Smithsonian's National Zoo's female giant Pacific octopus, died Tuesday.
The cephaloapod lived to be about 5 years old, making her the exhibit's longest-lived octopus.
The average giant octopus lives about 3 to 5 years, so her cause of death is suspected to be old age. The day before she died, zoo curators noticed Pandora had become lethargic and had lost much of her muscle tone -- a common indication of old age in her species.
A final pathology report is expected.
“She was a terrific ambassador for her species," Tamsen DeWitt, a biologist at the Invertebrate Exhibit, said. "She was curious, charismatic and taught us so much about octopus behavior. We’re happy she had such a long and healthy life.”