CAMDEN, N.J. (CBS) – Blue for a boy…. pink for a girl.

Cakes with colored filling inside are all the rage nowadays to announce a baby is on their way, but one gender reveal party Thursday had a bit of a twist.

It’s not every day one is held for a penguin, let alone a new born that is more than four months old like Topper.

But at Adventure Aquarium in Camden the cake was cut …with pink filling.

Topper is a girl! (Credit: John McDevitt)

Topper is a girl! (Credit: John McDevitt)

Biologist Kate Budion says when penguins are born, it’s not known if they are male or female:

“We wait a few months until they are not really baby birds anymore. So we wait until they are juveniles, our vet comes in, takes a blood sample, we actually send it away to a lab to get DNA tested, they send us back the results to let us know if it’s a boy or a girl.”

African penguins are endangered in the wild and Topper is a part of a species survival breeding program.

You can see Topper and the entire penguin colony waddling around on the Aquarium’s Penguin Island.