A ceremony to celebrate the 100th day of China's first hand-reared Pacific walrus was held on Monday in an ocean park in Zhuhai, Guangdong province.

The walrus, named Wowo, was born on June 8 at Chimelong Ocean Kingdom and provides insights for marine biodiversity conservation. It grew from 56 kilograms at birth to over 100 kilograms in its first 100 days, according to the ocean park.

The calf faced challenges immediately, as it was stuck in its mother's birth canal for nearly six hours. Once Wowo was born, the mother refused to recognize him and even attacked him. She wouldn't breastfeed her baby.

The care team adopted a multi-source milk approach, which combined orca milk, milk from other walruses, and artificial milk.

"We have established a Pacific walrus breeding database, including pregnancy diagnosis, prenatal care, postnatal care, and calf care, forming an effective breeding system," said Zhang Delu, general manager of the animal management department of Hengqin Chimelong Resort.

Pacific walruses are listed as endangered by the International Union for Conservation of Nature.