Two baby emperor penguins enjoy their 100-day anniversary in Laohutan Pole Aquarium in Dalian City, northeastern China. But one of them had a unique experience before meeting their parents.

A pair of mother penguins laid two eggs earlier this year. After days of incubation, one of them hatched successfully, but the other one showed no signs of coming out.

Fearing that the chick could die in the egg as the hatching was overdue the penguin keepers decided that the chick could survive with help from outside its shell.

The egg of a penguin is much larger and thicker than those of poultry. After a carefully planned surgery that lasted nearly 40 minutes, the chick was born healthy.

The keepers have developed an artificial penguin mouth to ensure that the chick eats enough. It now weighs 37 kilograms, 170 times heavier than when it was born.