Pandora, the female giant Pacific octopus at the Smithsonian’s National Zoo. (Abby Wood/Smithsonian’s National Zoo)

Washington’s favorite cephalopod, the National Zoo’s female giant octopus Pandora, has died, the zoo announced Wednesday.

Pandora was 5 years old, the upper range of the median life span for her species, when she died Feb. 11.

The cause of the octopus’s death is still unknown, although most octopuses die after breeding. Pandora had released unfertilized eggs, each the size of a grain of rice, in April 2013.

Zoo curators began to worry about Pandora on Feb. 10, when she started exhibiting the common signs of old age in octopuses: limited movement and less muscle tone.

More than 300 children from across Washington nominated names for Pandora in a Washington Post KidsPost contest shortly after she arrived at the zoo in November 2011.

“Our staff, volunteers and visitors that know her by name were very fond of her,” said Tamsen DeWitt, a biologist at the zoo’s invertebrate exhibit. “She was a terrific ambassador for her species. She was curious, charismatic and taught us so much about octopus behavior. We’re happy she had such a long and healthy life.”

Pandora’s species of octopus is true to its name as the largest octopus species in the world. Pandora, with a weight of 15.4 lbs. and an arm span of 7.8 feet, was about half the size of the maximum size of a giant octopus.