Hong Kong Ocean Park Monday celebrated the birthday of its four giant pandas, with Jia Jia, who is turning 38 this year, continues to hold the world record for the oldest panda ever.

The four pandas were presented icy cakes as birthday gifts. The older pair, Jia Jia and An An, got the peach-shaped cakes, while the younger pair, Ying Ying and Le Le, the star-shaped.

Jia Jia and An An, who set record for the world's oldest panda ever under human care and the world's second oldest male giant panda under human care respectively in July 2015, are turning 38 and 30 this year, the equivalent of 114 and 90 in human terms.

Monday is also Le Le's actual birthday, who is turning 11 years old this year along with Ying Ying.

Suzanne Gendron, the park's Executive Director of Zoological Operations and Education said Ying Ying and Le Le completed their sixth mating season in April this year.

Ying Ying received artificial insemination twice during the period.

Gendron said, currently, Ying Ying has shown a slowed appetite, hormonal changes and other typical early-pregnancy symptoms, but these symptoms may be caused by pseudo, or false pregnancy, common with pandas.

Since the gestation period for giant pandas lasts between 72 and 324 days, and it is difficult to confirm their pregnancy through ultrasound scans until two weeks before giving birth, she noted.

As for Jia Jia and An An, Gendron said, given their advanced years, the two are living with geriatric conditions such as high blood pressure and arthritic pain, yet they are considered in satisfactory health.

"Our animal care team will continue to offer them exemplary care to ensure they enjoy the highest quality of life in their sunset years," she added.