The Smithsonian's National Zoo says its two-week-old giant panda cub is a girl, and the daughter of the National Zoo's own Tian Tian.
The zoo made the announcement at a press event Thursday, revealing details about the cub and about a second stillborn cub, which was also a girl. Zoo officials say the cubs were fraternal twins.
The surviving panda cub has been described as healthy and active. Zookeepers conducted a 10-minute physical examination days after it was born. Veterinarians said the cub had a steady heartbeat and appeared to be digesting its food.
"She is absolutely beautiful," a zookeeper said at the Thursday morning event. "It has a fat little belly. It's very active, very vocal."
The panda's distinctive black and white markings are beginning to show, they said.
It takes time to determine a cub's gender. A DNA sample had to be taken to determine the cub's paternity.
Mei Xiang was artificially inseminated twice March 30 after failing to breed naturally with Tian Tian. Zoo officials say she was inseminated with fresh and previously frozen semen from both Tian Tian and Gao Gao, a panda at the San Diego Zoo.
Zoo officials say the insemination process did not contribute to the death of the second panda cub. A necropsy revealed the stillborn cub was missing part of her skull and brain, and had deformities with her eyes and jaw.
Mei Xiang has given birth to two cubs in the past. A female cub, born last September, lived only six days. Her birth was a surprise; she had not shown up on any ultrasounds. An autopsy determined she may have been born prematurely. Mei Xiang's only other surviving cub, Tai Shan, was born in 2005 and now lives in China.
U.S. & World
Mei Xiang is now eating and doing well, zookeepers said. But it will be about four months before the public gets an in-person glimpse of Mei Xiang and her cub.
As for a name, zoo officials say they will follow Chinese tradition and name the cub after 100 days. The zoo will consult with their colleagues in China to select a Chinese name. They hope to receive several options and then bring the zoo's guests in on the selection process.
According to an agreement with the Chinese government, the cub will stay at the National Zoo for four years and will then be sent to China.
The zoo says they have also talked about swapping out Mei Xiang or Tian Tian for another panda to keep the breeding program going. But Mei Xiang will remain at the zoo for at least two more years as she weans her cub.
Only four zoos in the United States have giant pandas.
RELATED COVERAGE ON NBCWashington.com: